Added "scrollThen" that can apply a scroll animation before another transition

Related to issue #76

Usage:

  this.transition(
    this.fromRoute('posts'),
    this.toRoute('post'),
    this.use('scrollThen', 'toLeft'),
    this.reverse('scrollThen', 'toRight', {duration: 100})
  );
Update transition-skeleton.js
Merge pull request #100 from stefanpenner/patch-1

Update transition-skeleton.js
Send actions from modal components

Adds an `actions` option, for example:

```javascript
this.modal(‘a-modal’, { 
  withParams: [‘bar’], 
  actions: { submit: “submitModal”} 
})
```
Merge pull request #101 from rlivsey/modal-actions

Send actions from modal components
RSVP compatibility update

Closes #102
Merge branch 'master' of github.com:ef4/liquid-fire
prefer an injection rule
bugfix: bind correctly to modal aria options
adding dialogClass option for modals
minor improvements to modal-popup transition
releasing
updating for newer addon format
vendoring sinon because there's no usable up-to-date bower package
re-adding package metadata
drop duplicate metadata
prevent ember assertion
fix links from test page
dropping this so we're compatible with ember-cli 1.2
changelog