Add Ceph as backup backend support

Cinder backup could use Ceph as backend.
This patch aims to create cinder::backup::ceph class to use this driver.

Change-Id: Ib82b94f3e2d5d9e2287a570a435d469656c9a756
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Fix default Swift URL in Backup service

Change-Id: I860fdf2173c2ea0a3a91f310455927f8115b14fe
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Merge "Add Ceph as backup backend support"
Add more granular logging support

cinder::logging provides the option to log cinder messages to
/var/log/cinder or to syslog. It also provides a minimal logging
threshold.
Added logging tests and moved to cinder_logging spec

Added new parameters to cinder class log_level and log_dir.

Change-Id: Iaa090083f66ae026c1ff5a4454a70390111734ac
Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>