Strange Added code

Hi there, I am inquiring about some code automatically added to my website which has caused some of the javascript and css to break. There was a link to font-awesome added to the header that I removed and it looks like some javascript, particularly a file called, gulpfile.js and some called package.json. I removed these because after the plugin was installed some sliders on our site broke. We are still getting errors, are there other places where the plugin injects code that I need to remove? I would like to resolve this problem. Thanks. Jenn