FIX problematic installation of c files.

When installing with sudo python3 setup.py install

The installed version of compAu was missing the c template files. To fix that my first attempt was to add the C template in the MANIFEST.in file as it is the suggested method to handle non python files in a python project: https://docs.python.org/2/distutils/sourcedist.html#the-manifest-in-template

When I noticed this could be fixed directly in setup.py I removed the MANIFEST.in and use that approach to minimize the amount of change on the project.