Update Contributing section in README.md to run the `gulp test` command rather than just `gulp`
Update Contributing section in README.md to run the `gulp test` command rather than just `gulp`

closeio/Autolinker.js,pratyushtewari/Autolinker.js,gregjacobs/Autolinker.js,gregjacobs/Autolinker.js,gregjacobs/Autolinker.js,closeio/Autolinker.js,closeio/Autolinker.js,pratyushtewari/Autolinker.js,closeio/Autolinker.js,gregjacobs/Autolinker.js