Empty UIActivityViewController specs.
Adds UIActivityController wrapper.
Adds the ability to return an array of constants if the Constant.get doesn't return a number.
Passing test for constants change.
Turns out Apple auto-sets a private transition style that can't be overridden:

17 (which doesn't exist in the UIModalTransitionStyle enum declaration).
Add tests for UIActivityViewController.
Merge branch 'refs/heads/activity-controller' into uiactivityviewcontroller

* refs/heads/activity-controller:
  Add tests for UIActivityViewController.
  Turns out Apple auto-sets a private transition style that can't be overridden:
  Passing test for constants change.
  Adds the ability to return an array of constants if the Constant.get doesn't return a number.
  Adds UIActivityController wrapper.

Conflicts:
	motion/ui/ui_activity_view_controller_wrapper.rb
	motion/util/constants.rb
	spec/motion/util/constants_spec.rb
Removed erroneously committed file.