Remove branch qualifier.

Author: Ayla Khan

README.md

@@ -1,6 +1,6 @@
 # ImplicitFunction
 
 [![Build Status](https://travis-ci.org/SCIInstitute/ImplicitFunction.svg?branch=master)](https://travis-ci.org/SCIInstitute/ImplicitFunction)
-[![Coverage Status](https://coveralls.io/repos/github/SCIInstitute/ImplicitFunction/badge.svg?branch=master)](https://coveralls.io/github/SCIInstitute/ImplicitFunction?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/SCIInstitute/ImplicitFunction/badge.svg)](https://coveralls.io/github/SCIInstitute/ImplicitFunction)
 
 Code to construct implicit RBF surfaces.