* Bump version to 6.0.0.
* sender option is now required.
* Default of want_proxmox_nodes_ansible_host changed from true to false.
* username is now an alias of user, and no longer of workspace.
* Remove deprecated return values in favor of end_state.
* Remove debug option.
* Change default of ignore_volatile_options from true to false.
* gitlab_group must now always contain the full path.
* Change default of norc from false to ture.
* Remove deprecated property.
* Add PR URL.
* Adjust bitbucket unit tests.
* Adjust module_helper integration test.
