Fix and enable integration tests against devel and stable-2.12 on Ubuntu1804

[Andersson007]

SUMMARY

Tests against devel and stable-2.12 on Ubuntu1804 have been disabled in #103.

Possibly because of ansible-collections/overview#45 (comment) (also maybe relates to the later announcements).

[Im0]

@Andersson007 where can I see a failed test? Thanks.

[Andersson007]

@Im0 you can

1. checkout this branch locally AZP: add stable-2.12 to test matrix #103 (clone it to ~/ansible_collections/community/rabbitmq)
2. uncomment ubuntu1804 in .azure-pipelines/azure-pipelines.yml that i commented
3. clone ansible/ansible repo, cd ansible/, source hacking/env-setup
4. run integration tests locally with ubuntu1804 container being in ~/ansible_collections/community/rabbitmq
ansible-test integration rabbitmq_publish --docker ubuntu1804 -vvv > ~/test.log. IIRC tests at least for rabbitmq_publish failed, so you can start with this as a target.

If any difficulties, I can uncomment them in my PR, no problem. Let me know if it's needed.

[Andersson007]

@Im0 option 2 is wait for my pr gets merged. Then you can update you local fork and do same with the main repo, not with my fork