[disks] Add file system for logical volumes and boot record

| partition | file system |
|-----------+-------------|
| root      | ext4        |
| swap      | swap        |
| nova      | xfs         |
| glance    | xfs         |
| boot raid | ext2        |
[tests] read_fixture method logs error message
[disks] add ability to define partition in release fixtures
[disks] Fix updating partitions, and size calculation for convertor
[disks] add tests for ceph
Remove constraints for roles in node model
Add ceph to redhat fixtures
PRD-1538 / integration tests for Ceph (WIP)