Update bourbon

Switch to un-prefixed border-radius. border-radius mixin was removed in
bourbon 3.0
Add rb-fsevent for guard; update guard-livereload
More border-radius related mixin removal
Destroy associated receipts with the delivery
Use Ember.run.later over setTimeout

Ensures the delay occurs within Ember's RunLoop
Add close button to autocomplete
Add loading animation view

Uses spin.js to build loading animation in CSS. Has two animation styles
, large and small. Defaults to small.
Remove wrapping <section> in deliveries/new
Improve UX on user autocomplete

* Disable input when searching
* Add loading spinner when searching
* Prevent selection/navigation when no results are present
Display loading animation when saving delivery
Use Node#has_css? options instead of just text
Prevent recipients from being added twice
Remember recipients across page refreshes