Add ansible_collection.py helper script
    
    The %collection_namespace and %collection_name macros are clunky. This
    script preforms two tasks:
        - install: extract the namespace, name, and version from galaxy.yml,
          run `ansible-galaxy install`, and write a filelist for use with
          %files -f.
    
        - test: create a temporary build directory with the required
          directory structure for ansible-test to work and run `ansible-test
          units`.