Adding Travis Continuous Integration to MoveIt

This will test build all commits, branches, and pull requests to ensure better code quality.

This PR is an initial test for just moveit_core - this same script should be able to be used for all of the moveit repositories. @isucan's email should probably be added to the email notification list once I finish testing this (it works in my fork thus far)

Thank you @jbohren for your help with learning Travis.