Update notes regarding phantomJS

[jacobq]

I noticed that on the ember-cli docs site there is reference to using phantomJS by default -- i.e.

• 2013-04-02-practices-windows.md
• 2013-04-03-common-issues.md
• 2013-04-11-testing.md
• 2014-04-03-getting-started

But in the recent past Ember has migrated away from phantomJS in favor of headless Chrome. Would someone be willing to help update the docs to explain the current state of things? I feel a little bad for not volunteering, but it's mainly because I am new to Ember testing and still trying to get a good handle on things myself :S.

Also, are there any plans to publish documentation for multiple versions of ember-cli (didn't get a reply when I had asked this over here)? Anything I can do to help with this?