There's a bunch of generated files that webpack relies on to work, and Karma works off webpack. To make both happy we've added
a new `build:genfiles` script which takes care of this for us. We also have to install and build our other layers to get the
same effect (like generating the react-sdk's component index, while we still have one).
This commit also fixes all the imports in the tests because they were just wrong. They should have been caught in the ES6ification
earlier, but were missed.