add coverage reporting

.coveragerc

@@ -0,0 +1,9 @@
+# -*- conf -*-
+
+[run]
+include =
+ ecdsa/*
+omit =
+ ecdsa/six.py
+ ecdsa/_version.py
+ ecdsa/test_ecdsa.py

.travis.yml

@@ -7,7 +7,10 @@ python:
   - "3.4"
   - "pypy"
   - "pypy3"
-install: true
+install:
+  - pip install python-coveralls
 script:
-  - python setup.py test
+  - coverage run setup.py test
   - python setup.py speed
+after_success:
+  - coveralls

README.md

@@ -1,6 +1,8 @@
 # Pure-Python ECDSA
 
 [![build status](https://travis-ci.org/warner/python-ecdsa.png)](http://travis-ci.org/warner/python-ecdsa)
+[![Coverage Status](https://coveralls.io/repos/warner/python-ecdsa/badge.svg)](https://coveralls.io/r/warner/python-ecdsa)
+[![Latest Version](https://pypip.in/version/ecdsa/badge.svg?style=flat)](https://pypi.python.org/pypi/ecdsa/)
 
 
 This is an easy-to-use implementation of ECDSA cryptography (Elliptic Curve