Add missing getter for waypoints and unit test for equality

Change-Id: If6ca25bd4459c32e30467991039bbbe36f2256f2
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/constraint/WaypointConstraint.java b/core/api/src/main/java/org/onlab/onos/net/intent/constraint/WaypointConstraint.java
index fffb66c..2a1e3e3 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/constraint/WaypointConstraint.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/constraint/WaypointConstraint.java
@@ -48,6 +48,10 @@
         this.waypoints = ImmutableList.copyOf(waypoints);
     }
 
+    public List<ElementId> waypoints() {
+        return waypoints;
+    }
+
     @Override
     public double cost(Link link, LinkResourceService resourceService) {
         // Always consider the number of hops