Update travis to install pillow to test image generation. Added cover…

…age to read.

.travis.yml

@@ -5,7 +5,7 @@ python:
     - 3.4
     - 3.5
 install:
-    - pip install numpy
+    - pip install pillow
     - pip install coverage
     - pip install coveralls
 script:

README.rst

@@ -1,11 +1,7 @@
 dicompyler-core
 ===============
 
-|pypi|
-
-|travis-ci|
-
-|Documentation Status|
+|pypi| |travis-ci| |coveralls| |Documentation Status|
 
 Core functionality of `dicompyler <http://www.dicompyler.com>`__. This
 package includes:
@@ -44,5 +40,7 @@ This package was created with
    :target: https://pypi.python.org/pypi/dicompyler-core
 .. |travis-ci| image:: https://img.shields.io/travis/dicompyler/dicompyler-core.svg
    :target: https://travis-ci.org/dicompyler/dicompyler-core
+.. |coveralls| image:: https://coveralls.io/repos/github/dicompyler/dicompyler-core/badge.svg?branch=master
+   :target: https://coveralls.io/github/dicompyler/dicompyler-core?branch=master
 .. |Documentation Status| image:: https://readthedocs.org/projects/dicompyler-core/badge/?version=latest
    :target: https://readthedocs.org/projects/dicompyler-core/?badge=latest