coffee-script dependency breaks install

[chrisboogz]

The coffee-script dependency (at least for me) no longer installs coffeescript and prints a warning to the console. Instead, it breaks the install:

$ npm install --save-dev electron-compilers
npm ERR! code E404
npm ERR! 404 Not Found: coffee-script@^1.10.0

Merging in this pull request should fix the issue.

[chrisboogz]

Turns out the error is because our out-of-date private npm repo isn't properly handling deprecation redirects. But it'd still be nice to have that dependency cleaned up!