Set our desired codeclimate engines, add badge.

Author: searls

.codeclimate.yml

@@ -1,3 +1,11 @@
+engines:
+  coffeelint:
+    enabled: true
+  fixme:
+    enabled: true
+  duplication:
+    enabled: true
+
 ratings:
   paths:
     - src/**

README.md

@@ -1,6 +1,7 @@
 # testdouble.js
 
 [![Build Status](https://secure.travis-ci.org/testdouble/testdouble.js.svg)](http://travis-ci.org/testdouble/testdouble.js) [![npmjs](https://img.shields.io/badge/npm-testdouble-red.svg)](https://www.npmjs.com/package/testdouble)
+[![Test Coverage](https://codeclimate.com/github/testdouble/testdouble.js/badges/coverage.svg)](https://codeclimate.com/github/testdouble/testdouble.js/coverage)
 
 Welcome! Are you writing JavaScript tests and in the market for a mocking library to
 fake out real things for you? testdouble.js is an opinionated, carefully-designed