[CORD-578] MPLS ECMP configurable

Changes:
- Adds MPLS-ECMP option to SR configuration;
- Updates the json examples;
- Implements unit tests to verify the expected behaviors;

Change-Id: I6a7f5d34161be7c85ecb76c9a09288d960aad3cb
diff --git a/src/test/resources/app-ecmp.json b/src/test/resources/app-ecmp.json
new file mode 100644
index 0000000..5c09001
--- /dev/null
+++ b/src/test/resources/app-ecmp.json
@@ -0,0 +1,20 @@
+{
+  "vRouterMacs" : [
+      "00:00:00:00:00:01",
+      "00:00:00:00:00:02"
+  ],
+  "vRouterId" : "of:1",
+  "suppressSubnet" : [
+      "of:1/1",
+      "of:1/2"
+  ],
+  "suppressHostByPort" : [
+      "of:1/1",
+      "of:1/2"
+  ],
+  "suppressHostByProvider" : [
+      "org.onosproject.provider.host",
+      "org.onosproject.netcfghost"
+  ],
+  "MPLS-ECMP" : true
+}