Separate cluster management and mastership management to separate packages

Change-Id: If1e399648451842da6dccc644b75b81337b105f9
diff --git a/core/api/src/main/java/org/onlab/onos/mastership/MastershipAdminService.java b/core/api/src/main/java/org/onlab/onos/mastership/MastershipAdminService.java
new file mode 100644
index 0000000..e558dd4
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/mastership/MastershipAdminService.java
@@ -0,0 +1,21 @@
+package org.onlab.onos.mastership;
+
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.MastershipRole;
+
+/**
+ * Service for administering the inventory of device masterships.
+ */
+public interface MastershipAdminService {
+
+    /**
+     * Applies the current mastership role for the specified device.
+     *
+     * @param instance controller instance identifier
+     * @param deviceId device identifier
+     * @param role     requested role
+     */
+    void setRole(NodeId instance, DeviceId deviceId, MastershipRole role);
+
+}