Add Coveralls README badge and Travis CI invocation.

Author: lapets

.travis.yml

@@ -8,8 +8,10 @@ python:
 cache: pip
 install:
   - pip install pylint
-  - pip install coverage
+  - pip install coveralls
   - pip install .
 script:
   - pylint published
   - nosetests
+after_success:
+  - coveralls

README.rst

@@ -4,7 +4,7 @@ published
 
 Python library that serves as an example/template for a package publishing guide.
 
-|pypi| |travis|
+|pypi| |travis| |coveralls|
 
 .. |pypi| image:: https://badge.fury.io/py/published.svg
    :target: https://badge.fury.io/py/published
@@ -13,6 +13,9 @@ Python library that serves as an example/template for a package publishing guide
 .. |travis| image:: https://travis-ci.com/python-supply/published.svg?branch=master
    :target: https://travis-ci.com/python-supply/published
 
+.. |coveralls| image:: https://coveralls.io/repos/github/python-supply/published/badge.svg?branch=master
+   :target: https://coveralls.io/github/python-supply/published?branch=master
+
 Purpose
 -------
 This library is an illustration of the various tasks and components involved in the process of publishing a small open-source Python package on PyPI, including establishment of linting standards, implementation of unit tests, measurement of coverage, and basic continuous integration.