Add build status badge to README.md

Author: tomreece

README.md

@@ -1,5 +1,7 @@
 # Magento Functional Testing Framework
 
+[![Build Status](https://travis-ci.com/magento/magento2-functional-testing-framework.svg?token=3FCSKYBzqzZZAxa2jjcc&branch=Travis-Codacy-Integration-Fix)](https://travis-ci.com/magento/magento2-functional-testing-framework)
+
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 ## System Requirements