[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/device.json b/src/test/resources/device.json
index 133f6d4..247d7f5 100644
--- a/src/test/resources/device.json
+++ b/src/test/resources/device.json
@@ -8,4 +8,4 @@
     { "adjSid" : 100, "ports" : [2, 3] },
     { "adjSid" : 200, "ports" : [4, 5] }
   ]
-}
\ No newline at end of file
+}