Add migrate mons module

[NotTheEvilOne]

This PR adds the module migrating Ceph mon daemons to Rook.

Closes #19

[boekhorstb1]

ok branch needs to be updated, rebase gives lots of conflicts.
Added backupbranch here: https://github.com/SovereignCloudStack/rookify/tree/backup/prs/add-migrate-mons-module

[boekhorstb1]

Please check:

I get no warning and no outputs when my setup misses configuration or has wrong configuration. Note, when addingg example to config.yaml, I get warnings. For example if there is no ceph configuration in .ceph:

# No usefull logs and no errors
migration_modules:
- bla

compare to:

# Usefull logs and lots of errors
migration_modules:
- example

@NotTheEvilOne

[NotTheEvilOne]

I added a separate issue (#56) for the described behavior as it is not part of the code changed with this PR.

[brueggemann]

I think the minimum number of running mons should be configurable via config file

[boekhorstb1]

Hi there!

ok the code worked after I deleted an existing configmap as describe in the issue here: #65

deletion is probably bad, I guess the check needs to be skipped if configmap allready exists @NotTheEvilOne

[brueggemann]

We should check, if librados has a timeout for a mon connection, and automatically switches over to another mon, as we are probably shutting down the mon we are connected to.

[brueggemann]

If this is not the case, we have to implement some timeout/reconnect in ceph.py