task: ceph: create monitor data directories prior to --mkfs

The new monitor store does not create the data directory on --mkfs. We
must create it instead, much like what happens with the osds.

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>

teuthology/task/ceph.py

@@ -665,6 +665,14 @@ def cluster(ctx, config):
     log.info('Running mkfs on mon nodes...')
     for remote, roles_for_host in mons.remotes.iteritems():
         for id_ in teuthology.roles_of_type(roles_for_host, 'mon'):
+            remote.run(
+                args=[
+                  'sudo',
+                  'mkdir',
+                  '-p',
+                  '/var/lib/ceph/mon/ceph-{id}'.format(id=id_),
+                  ],
+                )
             remote.run(
                 args=[
                     '{tdir}/enable-coredump'.format(tdir=testdir),