Update dependencies
* xitrum : 2.11 -> 2.13
* "xitrum-scalate : 1.3 -> 1.4
Fix #12 Update SBT from 0.13.0 to 0.13.1
Fix #12 Update SBT from 0.13.0 to 0.13.1
Update 2.13 to 2.15
https://groups.google.com/forum/#!topic/xitrum-framework/zW0ZlaTUf3o
Fix #13 Update Xitrum from 2.15 to 3.0
 * Add FutureAction example
Update readMe
Merge branch 'master' into heroku