mocha.js and mocha.css 
    
    are taken from https://github.com/Lindsay-Needs-Sleep/mocha.git#afa388dbf46c860748e4c387dd99010a922405ce

    This is a development version of 6.2.0

    Importantly, it includes Pull Request #3952  
    https://github.com/mochajs/mocha/pull/3952
    
chai.js
    is also included because it is just easier for hosting the chrome tests