input json-cov output and posts to coveralls.io

 Coveralls.io is a web service to help you track your code coverage over
 time, and ensure that all your new code is fully covered.
 .
 Coveralls automatically collects your code coverage data, uploads it
 to their servers and gives you a nice interface to dig into it.
 .
 This tools based on node.js allows one to post coverage information
 to coveralls.io
 .
 Node.js is an event-based server-side JavaScript engine.