Added travis integration

[bsaund]

Travis web page: https://travis-ci.com/UM-ARM-Lab/arc_utilities
(I'm curious if other UM-ARM-Lab github users have access automatically)

I'll add the travis link+image to the readme after this is merged in. Note the build on master is currently "failing" because there is no travis integration on master.

[cragoo]

I can see the travis page

[cragoo]

Nice, looks good to me. Is the setup script needed if you just ending executing catkin_make_isolated in test.sh anyways?

[bsaund]

setup.sh is not necessary. In other projects (see: mps_shape_completion) I use the setup script to pull in dependency repos.
I am including setup.sh

1. for consistency across projects
2. To make it easier for some later person to find a place to do additional setup, in case that is every needed

[cragoo]

Fair enough. Often I think these scripts are rarely looked at, so reducing the footprint of build files to a minimum makes it easier to sleuth build issues later on. Here that could be done by leaving the setup file empty except for a comment indicating that more code can be added.

In this case the files are pretty small so it doesn't matter much, but I'd thought I'd offer an alternative opinion.