chore(ci): add build status to README

Author: ryanolsonx

README.md

@@ -1,5 +1,7 @@
 # atom-ide-definitions package
 
+[![Build Status](https://api.travis-ci.org/atom-ide-community/atom-ide-definitions.png)](https://travis-ci.org/atom-ide-community/atom-ide-definitions)
+
 A replacement of the definitions functionality from the original Atom-IDE / Nuclide package developed by Facebook.
 
 ## Features