Green deployment

[ArseniiPetrovich]

As "Ansible" best practice says each play that does not change anything should result with "ok" status. However, even when we launch a deployment with the same configs we get something like

PLAY RECAP ***************************************************************
40.121.145.132             : ok=69   changed=5    unreachable=0    failed=0  

The root of this issue lies in the fact that some of the tasks, that does not actually change anything results with "changed" code. So, instead of totally "green" deployment we get "yellow-green", which leads to incorrect interpretation of deployment and may cause issues like #147.
What I propose is to refactor all the tasks to return "green" code when state remains unchanged.

[phahulin]

👍