Update the vendor folder (#53)

* Update the vendor folder

* Update the Gopkg.lock by running dep ensure

vendor/github.com/opencontainers/runc/PRINCIPLES.md

@@ -0,0 +1,19 @@
+# runc principles
+
+In the design and development of runc and libcontainer we try to follow these principles:
+
+(Work in progress)
+
+* Don't try to replace every tool. Instead, be an ingredient to improve them.
+* Less code is better.
+* Fewer components are better. Do you really need to add one more class?
+* 50 lines of straightforward, readable code is better than 10 lines of magic that nobody can understand.
+* Don't do later what you can do now. "//TODO: refactor" is not acceptable in new code.
+* When hesitating between two options, choose the one that is easier to reverse.
+* "No" is temporary; "Yes" is forever. If you're not sure about a new feature, say no. You can change your mind later.
+* Containers must be portable to the greatest possible number of machines. Be suspicious of any change which makes machines less interchangeable.
+* The fewer moving parts in a container, the better.
+* Don't merge it unless you document it.
+* Don't document it unless you can keep it up-to-date.
+* Don't merge it unless you test it!
+* Everyone's problem is slightly different. Focus on the part that is the same for everyone, and solve that.