How do I make catkin_make check for required python modules?

I would like for catkin_make to fail if a fellow developer does not have all of the required python modules installed. I thought that I could do this using the package.xml manifest, but I may just be doing something wrong. I would like to make sure that another developer has the python "requests" module installed on their system, but it could be any other non-standard python module from apt-get or pip. Am I on the right track? Should I try to add something to CMakeLists.txt to get this behavior? Here's a snippet of my package.xml file: awesomecatkinrospystd_msgsactionlibrospystd_msgsactionlibroslibossysjsonyamluuidboto3zipfilethreadingrequests