Summary: Adds new ```space-evenly``` for ```justify-content```. Also adds a typofix in one of the other justify-content tests. Fixes #657 Closes https://github.com/facebook/yoga/pull/658 Differential Revision: D6407996 Pulled By: emilsjolander fbshipit-source-id: cc837409e1345624b4bd72c31e25fe68dcb0f6a3