fix(collapse): trigger digest after

[Foxandxss]

.done is not triggering any $digest and we need that. .finally will do it (you can read the docs for that bit).

Fixes:

First one: If there is a hidden element on screen, $animateCss will compute its height:

Broken Plunker, no ngAnimate
(Works with ngAnimate)
Fixed Plunker, no ngAnimate
(Works the same with ngAnimate)

Second one: I don't know how to explain this one, but with $animateCss, it is not showing the navbar correctly (just drag it for the responsive behavior):

Broken Plunker, no ngAnimate
(Works with ngAnimate)
Fixed Plunker, no ngAnimate
(Works the same with ngAnimate)

Third one: Nested accordions not being rendered correctly:

Broken Plunker, no ngAnimate
(Works with ngAnimate)
Fixed Plunker, no ngAnimate
(Works the same with ngAnimate)

As you can see, the issue comes when you don't use ngAnimate.

There is also a bug that makes the animations to flicker, but that got fixed in 1.4.5 (1.3.x doesn't have the issue).

Fixes #4647
Fixes #4628
Fixes #4561

[Foxandxss]

Btw, I am not sure if this can be tested, animations are a mystery and I don't know if I simulate that I don't load ngAnimate (well, I don't think it is loaded, but I can't test those different behaviors).

[wesleycho]

LGTM