Remove empty service name

Before refreshing the service names and states for a group, the empty
service name should be removed if it exists. An empty service name may
exist where upon startup, a particular service was not found for a
member or members of a group.

Change-Id: I15d224231bb9db0823866393ec1776f793a3c126
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/zone.hpp b/control/zone.hpp
index 9565933..dbf4378 100644
--- a/control/zone.hpp
+++ b/control/zone.hpp
@@ -140,6 +140,15 @@
         };
 
         /**
+         * @brief Remove a service associated to a group
+         *
+         * @param[in] group - Group associated with service
+         * @param[in] name - Service name to remove
+         */
+        void removeService(const Group* group,
+                           const std::string& name);
+
+        /**
          * @brief Set or update a service name owner in use
          *
          * @param[in] group - Group associated with service