Figure out how to handle Python in venv for delegated tasks

[bjschafer]

Right now, the version check in the fluidd role relies on the github3 Python module. To avoid clutter on target Pis, the module is installed on the host running Ansible.

However, it seems that when running a task with delegate_to: localhost, Ansible finds the system default Python interpreter and not the one in the venv that it was invoked with.

For now, the workaround is to add a block like this in inventory.yaml:

all:
  hosts:
    localhost:
      ansible_connection: local
      ansible_python_interpreter: /path/to/your/venv/bin/python3

...and then run with ansible-playbook test-playbook.yaml --limit '!localhost'.