Add Build Status in the Readme file.
[![Build Status](https://travis-ci.com/manisacharya/node-calculator.svg?branch=master)](https://travis-ci.com/manisacharya/node-calculator)
Step 3 is optional and after the merge, you need to add your own handle of Travis-ci.
Issue number: Add Travis for CI #2
Description:
travis.yml
.package.json
.[![Build Status](https://travis-ci.com/manisacharya/node-calculator.svg?branch=master)](https://travis-ci.com/manisacharya/node-calculator)
Step 3 is optional and after the merge, you need to add your own handle of Travis-ci.