test(rxActionMenu): Tests and page objects.

Closes #525
I definitely feel the same way. As far as using these page objects is concerned, the big word is "convenience". If this gets deleted, there's not a lot this thing can do besides tell you what it says (and even then, who knows?).

There's a couple of ways to do this.

1. Delete all this code, and have everyone roll their own action menu constructor every time.
0. Just delete the `click` function, since `getText()` can yield `''` without breaking stuff.
0. Add a conditional `isPresent()` check to see if there's an icon there.

I kind of like that last one, since I'm pretty certain most users will be using the suggested styling for most components, which includes an icon in the action menu. But, if they don't, then `click` will just do nothing, which is better than `NoSuchElement` errors.

Now, as far as a long term solution goes, is there any way to enforce a more rigorous template for users to transclude into? Right now this directive is pretty html-heavy. Perhaps users can drive the action menu's contents based on scope, and the directive will fill out the "proper" html for you?