Fix db sync relationships

- The trove module does not specify a 'trove' package resource, so use
  the 'python-troveclient' package resource.
- The trove module does not specify a 'DEFAULT/sql_connection'
  keystone_config resource and has no need to manage keystone configs,
  so use trove_config.
- The trove module does not specify a 'trove' user. The trove user is
  created by the trove client package, which is already related by the
  subscribe metaparameter, so remove the require relationship.

Change-Id: I4e9ae0403439a51889e5fb884e689f91b874ad4d