Implement basic unit tests for RouteHandler

In addition,
    - Refactor Segment Routing unit test mocking

Change-Id: I94cb75a8b12944264faa76301d58ee19f246d584
diff --git a/src/test/java/org/onosproject/segmentrouting/MockSegmentRoutingManager.java b/src/test/java/org/onosproject/segmentrouting/MockSegmentRoutingManager.java
new file mode 100644
index 0000000..ad098b4
--- /dev/null
+++ b/src/test/java/org/onosproject/segmentrouting/MockSegmentRoutingManager.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.segmentrouting;
+
+import org.onosproject.core.DefaultApplicationId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Mock Segment Routing Manager.
+ */
+public class MockSegmentRoutingManager extends SegmentRoutingManager {
+    private Map<Integer, TrafficTreatment> nextTable;
+    private AtomicInteger atomicNextId = new AtomicInteger();
+
+    MockSegmentRoutingManager(Map<Integer, TrafficTreatment> nextTable) {
+        appId = new DefaultApplicationId(1, SegmentRoutingManager.APP_NAME);
+        this.nextTable = nextTable;
+    }
+
+    @Override
+    public int getPortNextObjectiveId(DeviceId deviceId, PortNumber portNum,
+                                      TrafficTreatment treatment,
+                                      TrafficSelector meta,
+                                      boolean createIfMissing) {
+        int nextId = atomicNextId.incrementAndGet();
+        nextTable.put(nextId, treatment);
+        return nextId;
+    }
+}