fix role tests

Ansible role tests were failing due to ansible-lint reporting
multiple errors.

Fixing those errors resolves the failing tests.

Switching gcsfuse to use gcloud's bootstrap to follow the current
docker install instructions.

Removing centos as it's a discontinued distribution.

Adding a check to ensure integration tests are skipped unless they
are run by a branch (a public fork does not pass required
integration test credentials).

molecule/gcloud/package_playbook.yml

@@ -3,7 +3,7 @@
   hosts: all
   pre_tasks:
     - name: Install gpg for apt_key
-      apt:
+      ansible.builtin.apt:
         name: gnupg
         update_cache: true
       when: ansible_os_family|lower == "debian"