Enable F22 without the FORCE flag

F22 has a stable release and working with devstack.

The change also removes the version flags regarding to the
mariadb-devel.

NOTE: You may see yum deprecation warnings, unless
you set the YUM variable to dnf.

Change-Id: I05140765bffc16faef5a29dfaba291c290bfae02
diff --git a/lib/ceph b/lib/ceph
index 4068e26..4d6ca4a 100644
--- a/lib/ceph
+++ b/lib/ceph
@@ -110,7 +110,7 @@
 
 # check_os_support_ceph() - Check if the operating system provides a decent version of Ceph
 function check_os_support_ceph {
-    if [[ ! ${DISTRO} =~ (trusty|f20|f21) ]]; then
+    if [[ ! ${DISTRO} =~ (trusty|f20|f21|f22) ]]; then
         echo "WARNING: your distro $DISTRO does not provide (at least) the Firefly release. Please use Ubuntu Trusty or Fedora 20 (and higher)"
         if [[ "$FORCE_CEPH_INSTALL" != "yes" ]]; then
             die $LINENO "If you wish to install Ceph on this distribution anyway run with FORCE_CEPH_INSTALL=yes"