Add coverage tests

README.md

@@ -1,7 +1,7 @@
 ## EWStools
 
 [![Build Status](https://travis-ci.org/jknowles/EWStools.png?branch=master)](https://travis-ci.org/jknowles/EWStools)
-
+[![Coverage Status](https://coveralls.io/repos/jknowles/EWStools/badge.svg?branch=master&service=github)](https://coveralls.io/github/jknowles/EWStools?branch=master)
 ### Overview
 
 `EWStools` is the source-code behind many of the modules within the [Wisconsin 
@@ -29,4 +29,4 @@ classification models on both test and training data.
 
 `EWStools` features wrapper code for `caret`'s `train` function which makes it 
 easy to build a sequential test of many model types available to `train` and 
-store the results of the test efficiently. 
+store the results of the test efficiently.