Remove deprecated features, bump version to 6.0.0 (#5326)

* 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.

galaxy.yml

@@ -5,7 +5,7 @@
 
 namespace: community
 name: general
-version: 5.8.0
+version: 6.0.0
 readme: README.md
 authors:
   - Ansible (https://github.com/ansible)