Adding coveralls badge.

Author: pykler

README.rst

@@ -6,6 +6,9 @@ yajl-py
 .. image:: https://travis-ci.org/pykler/yajl-py.png?branch=master
    :target: https://travis-ci.org/pykler/yajl-py
 
+.. image:: https://coveralls.io/repos/pykler/yajl-py/badge.png
+   :target: https://coveralls.io/r/pykler/yajl-py
+
 .. image:: https://pypip.in/v/yajl-py/badge.png
    :target: https://crate.io/packages/yajl-py/#info