Remove comments from Gopkg.toml and refer to the documentation

Those comments are added by default when doing a `dep init`. We don't
need them and can just refer to the documentation instead.

Signed-off-by: Vincent Demeester <vdemeest@redhat.com>

Gopkg.toml

@@ -1,28 +1,5 @@
-# Gopkg.toml example
-#
 # Refer to https://golang.github.io/dep/docs/Gopkg.toml.html
 # for detailed Gopkg.toml documentation.
-#
-# required = ["github.com/user/thing/cmd/thing"]
-# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
-#
-# [[constraint]]
-#   name = "github.com/user/project"
-#   version = "1.0.0"
-#
-# [[constraint]]
-#   name = "github.com/user/project2"
-#   branch = "dev"
-#   source = "github.com/myfork/project2"
-#
-# [[override]]
-#   name = "github.com/x/y"
-#   version = "2.4.0"
-#
-# [prune]
-#   non-go = false
-#   go-tests = true
-#   unused-packages = true
 
 required = [
   "github.com/tektoncd/plumbing/scripts",