vendor: use versions when possible in glide.yaml

Now using tags instead of SHAs

cmd/vendor/github.com/prometheus/procfs/fs.go

@@ -27,14 +27,7 @@ func NewFS(mountPoint string) (FS, error) {
 	return FS(mountPoint), nil
 }
 
-func (fs FS) stat(p string) (os.FileInfo, error) {
-	return os.Stat(path.Join(string(fs), p))
-}
-
-func (fs FS) open(p string) (*os.File, error) {
-	return os.Open(path.Join(string(fs), p))
-}
-
-func (fs FS) readlink(p string) (string, error) {
-	return os.Readlink(path.Join(string(fs), p))
+// Path returns the path of the given subsystem relative to the procfs root.
+func (fs FS) Path(p ...string) string {
+	return path.Join(append([]string{string(fs)}, p...)...)
 }