Update README.md

Author: gkorland

README.md

@@ -4,7 +4,7 @@
 [![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.redislabs/jrejson/badge.svg)](https://maven-badges.herokuapp.com/maven-central/com.redislabs/jrejson)
 [![Javadocs](https://www.javadoc.io/badge/com.redislabs/jrejson.svg)](https://www.javadoc.io/doc/com.redislabs/jrejson)
 [![Codecov](https://codecov.io/gh/RedisJSON/JRedisJSON/branch/master/graph/badge.svg)](https://codecov.io/gh/RedisJSON/JRedisJSON)
-
+[![Language grade: Java](https://img.shields.io/lgtm/grade/java/g/RedisJSON/JRedisJSON.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/RedisJSON/JRedisJSON/context:java)
 
 
 # JRedisJSON