[opencontrail] Use suggests instead of depends for cassandra, zookeeper and redis-server

Relax dependency in order to be able to install cassandra, zookeeper and
redis-server on another servers than contrail srv.
[services] Finish renaming and clean services
Merge pull request #17 from sbadia/rename

[services] Finish renaming and clean services
Merge pull request #16 from sbadia/suggests

[opencontrail] Use suggests instead of depends for cassandra, zookeeper and redis-server