switch to vndr

vndr is almost exactly the same as our old good hack/vendor.sh. Except
it's cleaner and it allows to re-vendor just one dependency if needed
(which we do a lot for containers/image).

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/go-check/check/.gitignore

@@ -1,4 +0,0 @@
-_*
-*.swp
-*.[568]
-[568].out

vendor/github.com/go-check/check/.travis.yml

@@ -1,3 +0,0 @@
-language: go
-
-go_import_path: gopkg.in/check.v1

vendor/github.com/go-check/check/README.md

@@ -1,20 +0,0 @@
-Instructions
-============
-
-Install the package with:
-
-    go get gopkg.in/check.v1
-    
-Import it with:
-
-    import "gopkg.in/check.v1"
-
-and use _check_ as the package name inside the code.
-
-For more details, visit the project page:
-
-* http://labix.org/gocheck
-
-and the API documentation:
-
-* https://gopkg.in/check.v1

vendor/github.com/go-check/check/TODO

@@ -1,2 +0,0 @@
-- Assert(slice, Contains, item)
-- Parallel test support