Merge pull request ExpDev07#101 from gribok/master

Add build status of travis ci to README

Author: ExpDev07

README.md

@@ -8,6 +8,7 @@
 ![GitHub last commit](https://img.shields.io/github/last-commit/ExpDev07/coronavirus-tracker-api)
 ![GitHub pull requests](https://img.shields.io/github/issues-pr/ExpDev07/coronavirus-tracker-api)
 ![GitHub issues](https://img.shields.io/github/issues/ExpDev07/coronavirus-tracker-api)
+![Travis build](https://api.travis-ci.com/ExpDev07/coronavirus-tracker-api.svg?branch=master)
 [![Tweet](https://img.shields.io/twitter/url?url=https%3A%2F%2Fgithub.com%2FExpDev07%2Fcoronavirus-tracker-api)](https://twitter.com/intent/tweet?text=COVID19%20Live%20Tracking%20API:%20&url=https%3A%2F%2Fgithub.com%2FExpDev07%2Fcoronavirus-tracker-api)
 
 ## Endpoints