default_caps are not up to date with ceph-mon: mon capabilities include write permissions

[Dmitrii Shcherbakov]

Currently default_caps in charm-ceph-proxy include this for newly created users:

_default_caps = {
    'mon': ['allow rw'],
    'osd': ['allow rwx']
}

While ceph-mon caps are as follows:
https://github.com/openstack/charm-ceph-mon/blob/stable/18.08/lib/ceph/utils.py#L1097-L1101
_default_caps = collections.OrderedDict([
    ('mon', ['allow r',
             'allow command "osd blacklist"']),
    ('osd', ['allow rwx']),
])

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/604745

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/604745
Committed: https://git.openstack.org/cgit/openstack/charm-ceph-proxy/commit/?id=331e8451c6130fa6ce5d356a52c94f2ac78f4190
Submitter: Zuul
Branch: master

commit 331e8451c6130fa6ce5d356a52c94f2ac78f4190
Author: Dmitrii Shcherbakov <email address hidden>
Date: Thu Sep 20 04:35:29 2018 +0300

    modify default_caps to match current ceph-mon caps

    The current default caps in ceph-proxy are not up to date with
    charm-ceph-mon caps.

    Change-Id: Iaeb8d4dea9c36f522aeaddf54b19e4947c81a559
    Closes-Bug: #1794071