joint_limits_interface broken in Groocy and Hydro

Hey Groovy and Hydro folks,

I just realized that the `joint_limits_interface` package has a URDF dependency, which in Fuerte is `urdf_interface`, and since Groovy is `urdfdom`. Building the tests for this package should be broken ,as the dependency got removed in recent commits/merges. This PR should address the issue. Please review and accept if correct.

@jbohren, @davetcoleman