use dep as denpendency managment tool

vendor/github.com/googleapis/gnostic/compiler/README.md

@@ -0,0 +1,3 @@
+# Compiler support code
+
+This directory contains compiler support code used by Gnostic and Gnostic extensions.

vendor/github.com/googleapis/gnostic/compiler/reader.go

@@ -110,7 +110,9 @@ func ReadInfoFromBytes(filename string, bytes []byte) (interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	infoCache[filename] = info
+	if len(filename) > 0 {
+		infoCache[filename] = info
+	}
 	return info, nil
 }