Add go report card

Author: Fabio Hiroki

README.md

@@ -1,5 +1,7 @@
 # go-algorithms-data-structures
 
 [![CircleCI](https://circleci.com/gh/fabiothiroki/go-algorithms-data-structures/tree/master.svg?style=svg)](https://circleci.com/gh/fabiothiroki/go-algorithms-data-structures/tree/master)
+[![Go Report Card](https://goreportcard.com/badge/github.com/fabiothiroki/go-algorithms-data-structures)](https://goreportcard.com/report/github.com/fabiothiroki/go-algorithms-data-structures)
+
 
 Resolutions of common algorithms and data structures problems in Golang