Update MOD-19: Progress Bar

After testing in staging, I feel like using a progress bar automatically on all API requests is the wrong idea. For example, searching with the progress bar running is awkward and doesn't make any UX sense. So I've taken out the Restangular hook that was invoking the progress bar.

The progress bar is still invoked automatically on state changes.

In the future we may have some API calls that we want to show the progress bar for—in which case we'll just have to create manual `ProgressTask`s for them.