Make Course form compatible with Backbone 1.0.0

Instructure updated Backbone from 0.9.2 to 1.0.0, and that broke our Start a New Course form. We were listening to an event that is no longer being triggered (`reset`), which caused the perpetual "Loading..." problem.

This patch addresses these Backbone changes:

* In Backbone 0.9.9, the `request` event was added to `Backbone.sync`, so the `Collection#fetch` override to trigger `request` is no longer needed.
* In Backbone 1.0.0, the default updating mechanism after a fetch no longer triggers `reset`. Use the `sync` event instead.