Add HashiCorp Nomad provider (#483)

* provider: adding Nomad provider

* updating CONTRIBUTING.md with Nomad provider

* updated README.md by adding the Nomad provider

* fix typo

* adding nomad/api and nomad/testutil deps

* adding Nomad binary dependency for provider tests

* fixed the nomad binary download command step and added tolerations to the nomad provider.

* adding nomad provider demo gif

* adding my name to authors

* adding two missing go-rootcerts files after dep ensure

* delete pod comment

vendor/github.com/mitchellh/copystructure/copier_time.go

@@ -0,0 +1,15 @@
+package copystructure
+
+import (
+	"reflect"
+	"time"
+)
+
+func init() {
+	Copiers[reflect.TypeOf(time.Time{})] = timeCopier
+}
+
+func timeCopier(v interface{}) (interface{}, error) {
+	// Just... copy it.
+	return v.(time.Time), nil
+}