.travis.yml: continuously check the patch files
.travis.yml: continuously check the patch files

This commit enables to use travis ci for continuous integration.
As bash is not a valid programming language setup for travis,
I simply used the default ruby environment, which also provides
a proper shell interpreter.

bulwahn/meta-ros,bulwahn/meta-ros,rapyuta/meta-ros,bmwcarit/meta-ros,rapyuta/meta-ros,simium/meta-ros,bmwcarit/meta-ros,simium/meta-ros,bmwcarit/meta-ros,rapyuta/meta-ros,bmwcarit/meta-ros,simium/meta-ros,bulwahn/meta-ros,KristofRobot/meta-ros,KristofRobot/meta-ros