chore: add badge for goreportcard

Author: chriscasola

README.md

@@ -1,6 +1,7 @@
 # NLP
 
 [![CircleCI](https://circleci.com/gh/chriscasola/nlp.svg?style=svg)](https://circleci.com/gh/chriscasola/nlp)
+[![Go Report Card](https://goreportcard.com/badge/github.com/chriscasola/nlp)](https://goreportcard.com/report/github.com/chriscasola/nlp)
 [![GoDoc](https://godoc.org/github.com/chriscasola/nlp?status.svg)](https://godoc.org/github.com/chriscasola/nlp)
 
 NLP is a go package meant to contain implementations of common natural language processing algorithms. So far there