Add codecov

Author: Luka Bratos

.travis.yml

@@ -5,7 +5,10 @@ python:
 install:
   - pip install -Ur requirements.txt
   - pip install -Ur dev_requirements.txt
+  - pip install codecov
 script:
   - python -m pylint ./pusher_push_notifications/*.py
-  - python -m nose -s
+  - python -m nose -s --with-coverage
   - python setup.py checkdocs
+after_success:
+  - codecov

README.rst

@@ -1,5 +1,7 @@
 .. image:: https://travis-ci.org/pusher/push-notifications-python.svg?branch=master
    :target: https://travis-ci.org/pusher/push-notifications-python
+.. image:: https://codecov.io/gh/pusher/push-notifications-python/branch/master/graph/badge.svg
+  :target: https://codecov.io/gh/pusher/push-notifications-python
 
 Pusher Beams Python server SDK
 ==============================