Marco Umpiérrez

[Documentation] Missing property isAborted in Transition class

2

### 📙 Describe the Issue The property `isAborted` is missing from the class `Transition` although this property still exists. I've tried to find it in the old API docs but...

I didn't modify the logic of the `index.js` in this PR until I can have a better look at it.

Updated ember to version 3.2.0 and tests.