Make mongo install for ceilometer NOPRIME

mongodb packages are missing on some platforms, so we switch to a
manual install.  Also gate the mongo call in cleanup

Change-Id: I1755e461c66be30da3db2a0994f908503c4c38ea
diff --git a/files/rpms/ceilometer-collector b/files/rpms/ceilometer-collector
index c91bac3..9cf580d 100644
--- a/files/rpms/ceilometer-collector
+++ b/files/rpms/ceilometer-collector
@@ -1,4 +1,4 @@
 selinux-policy-targeted
-mongodb-server
-pymongo
+mongodb-server #NOPRIME
+pymongo # NOPRIME
 mongodb # NOPRIME