Added NSScreencast RubyMotion video
Add Learn Git Branching interactive tutorial

* Add to Git trail
Add Travis build status badge to README.md
Update links from blip.tv to youtube

* Scott Chacon's talks have moved from blip.tv to youtube
Update links in README.md

* GitHub now prepends `https://github/com/thoughtbot/trail-map/blob/master/` to local links
* Updated repo links, contributors, and contribution guideline links
Add UUIDs to trails

* Also turns validations into dictionary objects, instead of a simple
array.
* Add UUIDs to valid json fixture
Add UUID generation rake task

* Will assign UUIDs to any item that doesn't already have one.
* Can be run from generate:uuid
* Converted hashes to 1.9 syntax