This PR contains the following change:

• Creation/Deletion of Docker networks via the create.yml and delete.yml playbooks;

A filter molecule_get_docker_networks will be used that checks if a networks key is configured in the platforms. If so, it then checks if it has a name key and if that exists to, this name will be used with creating or deleting the docker network. If no networks key is configured in the platform (Or if so, but has no name key), then an empty list is returned and task is skipped.

Example usage for molecule.yml:

platforms:
  - name: ansible-docker
    image: milcom/centos7-systemd
    groups:
      - group1
    privileged: True
    networks:
      - name: my_fancy_network

If a better approach is needed, please let me know and I'll try again.
(I hope I have updated all correct test files :-) )