add codeclimate maintainability

Author: kevinohara80

README.md

@@ -1,6 +1,7 @@
 # SFDC trigger framework
 
 [![npm version](https://badge.fury.io/js/sfdc-trigger-framework.svg)](https://badge.fury.io/js/sfdc-trigger-framework)
+[![Maintainability](https://api.codeclimate.com/v1/badges/eeeae5a492e34feace99/maintainability)](https://codeclimate.com/github/kevinohara80/sfdc-trigger-framework/maintainability)
 
 I know, I know...another trigger framework. Bear with me. ;)