Mandatory dependency on rostest

[jvgomez]

Hi,

I have noticed that the dependency on rostest is always there. In other packages (TF example) rostest is only find-packaged if CATKIN_ENABLE_TESTING is true. Reference issue

I wonder whether there is a reason for not doing the same in this package.

[jvgomez]

Ping. I am interested on knowing the answer to know whether I should do a PR with the fix here (to indigo-devel) or to meta-ros with the corresponding patch.

[tfoote]

Moving the rostest dependency inside the conditional is better. You can then also move it to be a test_depend in the package.xml