Ceph

This test is currently testing a few messages. It would be nice if we could increase the coverage, with the following scenarios in mind:

- monitors should ignore messages from non-monitors
- monitors should handle proper client requests and return success
- monitors should not handle malformed client requests and return error
- monitors should not die

Once we have a proper test, it should then be exercised either by `make check` or by a workunit to be run by teuthology.