Update to use go modules (#671)

This includes updates to CI config, vendor files, etc.
I've hard-coded the k8s depedency at 1.13.4 to keep it inline with what
we currently have and to make sure a another run of `go mod tidy`
doesn't accidentally update it to an unexpected version.

Thanks to hectorj2f for carrying this along.

vendor/github.com/pkg/errors/.gitignore

@@ -0,0 +1,24 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof

vendor/github.com/pkg/errors/.travis.yml

@@ -0,0 +1,15 @@
+language: go
+go_import_path: github.com/pkg/errors
+go:
+  - 1.4.x
+  - 1.5.x
+  - 1.6.x
+  - 1.7.x
+  - 1.8.x
+  - 1.9.x
+  - 1.10.x
+  - 1.11.x
+  - tip
+
+script:
+  - go test -v ./...

vendor/github.com/pkg/errors/README.md

@@ -0,0 +1,52 @@
+# errors [![Travis-CI](https://travis-ci.org/pkg/errors.svg)](https://travis-ci.org/pkg/errors) [![AppVeyor](https://ci.appveyor.com/api/projects/status/b98mptawhudj53ep/branch/master?svg=true)](https://ci.appveyor.com/project/davecheney/errors/branch/master) [![GoDoc](https://godoc.org/github.com/pkg/errors?status.svg)](http://godoc.org/github.com/pkg/errors) [![Report card](https://goreportcard.com/badge/github.com/pkg/errors)](https://goreportcard.com/report/github.com/pkg/errors) [![Sourcegraph](https://sourcegraph.com/github.com/pkg/errors/-/badge.svg)](https://sourcegraph.com/github.com/pkg/errors?badge)
+
+Package errors provides simple error handling primitives.
+
+`go get github.com/pkg/errors`
+
+The traditional error handling idiom in Go is roughly akin to
+```go
+if err != nil {
+        return err
+}
+```
+which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.
+
+## Adding context to an error
+
+The errors.Wrap function returns a new error that adds context to the original error. For example
+```go
+_, err := ioutil.ReadAll(r)
+if err != nil {
+        return errors.Wrap(err, "read failed")
+}
+```
+## Retrieving the cause of an error
+
+Using `errors.Wrap` constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by `errors.Cause`.
+```go
+type causer interface {
+        Cause() error
+}
+```
+`errors.Cause` will recursively retrieve the topmost error which does not implement `causer`, which is assumed to be the original cause. For example:
+```go
+switch err := errors.Cause(err).(type) {
+case *MyError:
+        // handle specifically
+default:
+        // unknown error
+}
+```
+
+[Read the package documentation for more information](https://godoc.org/github.com/pkg/errors).
+
+## Contributing
+
+We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.
+
+Before proposing a change, please discuss your change by raising an issue.
+
+## License
+
+BSD-2-Clause

vendor/github.com/pkg/errors/appveyor.yml

@@ -0,0 +1,32 @@
+version: build-{build}.{branch}
+
+clone_folder: C:\gopath\src\github.com\pkg\errors
+shallow_clone: true # for startup speed
+
+environment:
+  GOPATH: C:\gopath
+
+platform:
+  - x64
+
+# http://www.appveyor.com/docs/installed-software
+install:
+  # some helpful output for debugging builds
+  - go version
+  - go env
+  # pre-installed MinGW at C:\MinGW is 32bit only
+  # but MSYS2 at C:\msys64 has mingw64
+  - set PATH=C:\msys64\mingw64\bin;%PATH%
+  - gcc --version
+  - g++ --version
+
+build_script:
+  - go install -v ./...
+
+test_script:
+  - set PATH=C:\gopath\bin;%PATH%
+  - go test -v ./...
+
+#artifacts:
+#  - path: '%GOPATH%\bin\*.exe'
+deploy: off

vendor/github.com/pkg/errors/errors.go

@@ -6,7 +6,7 @@
 //             return err
 //     }
 //
-// which applied recursively up the call stack results in error reports
+// which when applied recursively up the call stack results in error reports
 // without context or debugging information. The errors package allows
 // programmers to add context to the failure path in their code in a way
 // that does not destroy the original value of the error.
@@ -15,16 +15,17 @@
 //
 // The errors.Wrap function returns a new error that adds context to the
 // original error by recording a stack trace at the point Wrap is called,
-// and the supplied message. For example
+// together with the supplied message. For example
 //
 //     _, err := ioutil.ReadAll(r)
 //     if err != nil {
 //             return errors.Wrap(err, "read failed")
 //     }
 //
-// If additional control is required the errors.WithStack and errors.WithMessage
-// functions destructure errors.Wrap into its component operations of annotating
-// an error with a stack trace and an a message, respectively.
+// If additional control is required, the errors.WithStack and
+// errors.WithMessage functions destructure errors.Wrap into its component
+// operations: annotating an error with a stack trace and with a message,
+// respectively.
 //
 // Retrieving the cause of an error
 //
@@ -38,7 +39,7 @@
 //     }
 //
 // can be inspected by errors.Cause. errors.Cause will recursively retrieve
-// the topmost error which does not implement causer, which is assumed to be
+// the topmost error that does not implement causer, which is assumed to be
 // the original cause. For example:
 //
 //     switch err := errors.Cause(err).(type) {
@@ -48,16 +49,16 @@
 //             // unknown error
 //     }
 //
-// causer interface is not exported by this package, but is considered a part
-// of stable public API.
+// Although the causer interface is not exported by this package, it is
+// considered a part of its stable public interface.
 //
 // Formatted printing of errors
 //
 // All error values returned from this package implement fmt.Formatter and can
-// be formatted by the fmt package. The following verbs are supported
+// be formatted by the fmt package. The following verbs are supported:
 //
 //     %s    print the error. If the error has a Cause it will be
-//           printed recursively
+//           printed recursively.
 //     %v    see %s
 //     %+v   extended format. Each Frame of the error's StackTrace will
 //           be printed in detail.
@@ -65,13 +66,13 @@
 // Retrieving the stack trace of an error or wrapper
 //
 // New, Errorf, Wrap, and Wrapf record a stack trace at the point they are
-// invoked. This information can be retrieved with the following interface.
+// invoked. This information can be retrieved with the following interface:
 //
 //     type stackTracer interface {
 //             StackTrace() errors.StackTrace
 //     }
 //
-// Where errors.StackTrace is defined as
+// The returned errors.StackTrace type is defined as
 //
 //     type StackTrace []Frame
 //
@@ -85,8 +86,8 @@
 //             }
 //     }
 //
-// stackTracer interface is not exported by this package, but is considered a part
-// of stable public API.
+// Although the stackTracer interface is not exported by this package, it is
+// considered a part of its stable public interface.
 //
 // See the documentation for Frame.Format for more details.
 package errors
@@ -192,7 +193,7 @@ func Wrap(err error, message string) error {
 }
 
 // Wrapf returns an error annotating err with a stack trace
-// at the point Wrapf is call, and the format specifier.
+// at the point Wrapf is called, and the format specifier.
 // If err is nil, Wrapf returns nil.
 func Wrapf(err error, format string, args ...interface{}) error {
 	if err == nil {
@@ -220,6 +221,18 @@ func WithMessage(err error, message string) error {
 	}
 }
 
+// WithMessagef annotates err with the format specifier.
+// If err is nil, WithMessagef returns nil.
+func WithMessagef(err error, format string, args ...interface{}) error {
+	if err == nil {
+		return nil
+	}
+	return &withMessage{
+		cause: err,
+		msg:   fmt.Sprintf(format, args...),
+	}
+}
+
 type withMessage struct {
 	cause error
 	msg   string

vendor/github.com/pkg/errors/stack.go

@@ -46,7 +46,8 @@ func (f Frame) line() int {
 //
 // Format accepts flags that alter the printing of some verbs, as follows:
 //
-//    %+s   path of source file relative to the compile time GOPATH
+//    %+s   function name and path of source file relative to the compile time
+//          GOPATH separated by \n\t (<funcname>\n\t<path>)
 //    %+v   equivalent to %+s:%d
 func (f Frame) Format(s fmt.State, verb rune) {
 	switch verb {
@@ -79,6 +80,14 @@ func (f Frame) Format(s fmt.State, verb rune) {
 // StackTrace is stack of Frames from innermost (newest) to outermost (oldest).
 type StackTrace []Frame
 
+// Format formats the stack of Frames according to the fmt.Formatter interface.
+//
+//    %s	lists source files for each Frame in the stack
+//    %v	lists the source file and line number for each Frame in the stack
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+v   Prints filename, function, and line number for each Frame in the stack.
 func (st StackTrace) Format(s fmt.State, verb rune) {
 	switch verb {
 	case 'v':
@@ -136,43 +145,3 @@ func funcname(name string) string {
 	i = strings.Index(name, ".")
 	return name[i+1:]
 }
-
-func trimGOPATH(name, file string) string {
-	// Here we want to get the source file path relative to the compile time
-	// GOPATH. As of Go 1.6.x there is no direct way to know the compiled
-	// GOPATH at runtime, but we can infer the number of path segments in the
-	// GOPATH. We note that fn.Name() returns the function name qualified by
-	// the import path, which does not include the GOPATH. Thus we can trim
-	// segments from the beginning of the file path until the number of path
-	// separators remaining is one more than the number of path separators in
-	// the function name. For example, given:
-	//
-	//    GOPATH     /home/user
-	//    file       /home/user/src/pkg/sub/file.go
-	//    fn.Name()  pkg/sub.Type.Method
-	//
-	// We want to produce:
-	//
-	//    pkg/sub/file.go
-	//
-	// From this we can easily see that fn.Name() has one less path separator
-	// than our desired output. We count separators from the end of the file
-	// path until it finds two more than in the function name and then move
-	// one character forward to preserve the initial path segment without a
-	// leading separator.
-	const sep = "/"
-	goal := strings.Count(name, sep) + 2
-	i := len(file)
-	for n := 0; n < goal; n++ {
-		i = strings.LastIndex(file[:i], sep)
-		if i == -1 {
-			// not enough separators found, set i so that the slice expression
-			// below leaves file unmodified
-			i = -len(sep)
-			break
-		}
-	}
-	// get back to 0 or trim the leading separator
-	file = file[i+len(sep):]
-	return file
-}