Revert "Bug 937630 - Remove scaling transition of lock screen to make it 60fps"

This reverts commit 9b3f7e22f7b548f10f07ba55293a682a5a2ed7bf.

The Lockscreen components partially cover the application surface.
Bug 907177 - [Clock] Add integration tests

r=iliu
Only run Clock integration tests

...for debugging purposes.
Use test abstraction's method
Run a whole bunch of jobs with debugging
Use real NPM registry

...since my Marionette plugin module isn't currently available in Gaia's
NPM cache.
Make navigation deterministic possibly