docs(readme): correct the Travis CI Badge URL to point to the master …

…branch

README.md

@@ -1,7 +1,7 @@
 <h1 align="center">Welcome to README Coverage Badger 👋</h1>
 
 [![PyPi](https://img.shields.io/pypi/v/readme-coverage-badger.svg)](https://pypi.python.org/pypi/readme-coverage-badger)
-[![Build Status](https://img.shields.io/travis/engineervix/readme-coverage-badger.svg)](https://travis-ci.com/engineervix/readme-coverage-badger)
+[![Build Status](https://travis-ci.com/engineervix/readme-coverage-badger.svg?branch=master)](https://travis-ci.com/engineervix/readme-coverage-badger)
 [![Updates](https://pyup.io/repos/github/engineervix/readme-coverage-badger/shield.svg)](https://pyup.io/repos/github/engineervix/readme-coverage-badger/)
 [![License](https://img.shields.io/badge/License-BSD%203--Clause-blue.svg)](https://opensource.org/licenses/BSD-3-Clause)
 [![codecov](https://codecov.io/gh/engineervix/readme-coverage-badger/branch/master/graph/badge.svg)](https://codecov.io/gh/engineervix/readme-coverage-badger)