add catkin_INCLUDE_DIRS to cob_kinematics

Example of break: http://csc.mcs.sdsmt.edu/jenkins/job/ros-indigo-cob-kinematics_binaryrpm_heisenbug_x86_64/9/console

I'm guessing that this works on your system because the urdf headers are placed directly in `/usr/include` while in Fedora, they are not.

Thanks,

--scott