OneJS control generator

Modified `yo onejs` to prompt the user to either generate an app, control, or testFramework. Also allows for command line arguments, see README for details, or try it yourself :smiley: 

The control option:
* Creates a dir `src/{control_name}`
* 4 files in that dir:
     * {control_name}.html
     * {control_name}.less
     * {control_name}Base.ts
     * {control_name}Model.ts
* A Chai test stub: `test/{control_name}.test.ts` with a basic assertion

The app option:
* Does what it did before (create root app, create a control based on name passed in)
* Creates a Chai test stub for the example control with a basic assertion
* Scaffolds the Karma/Chai/Mocha/Webpack test framework
* Has an updated gulpfile

The awesome thing about control/app generation is that you can immediately run `gulp test` and see a successful pass!

The testFramework option:
* Copies over our best practice version of Karma/Chai/Mocha/Webpack test framework