ONOS-3795 PATCH method in RestSbController and basic unit tests

Change-Id: I35dc31ab03fc72c11523b2c60f4455d7446a5364
diff --git a/providers/rest/app/features.xml b/providers/rest/app/features.xml
index 168ae55..db9f5ee 100644
--- a/providers/rest/app/features.xml
+++ b/providers/rest/app/features.xml
@@ -25,6 +25,8 @@
 
         <bundle>mvn:com.sun.jersey/jersey-client/1.19</bundle>
         <bundle>mvn:commons-io/commons-io/2.4</bundle>
+        <bundle>mvn:org.apache.httpcomponents/httpclient-osgi/4.5.1</bundle>
+        <bundle>mvn:org.apache.httpcomponents/httpcore-osgi/4.4.4</bundle>
     </feature>
 </features>