Add a set of unit tests for openstack telemetry app

Change-Id: Ib5963c61ef0c0302a90a4f30d3dd1f0ec2862aea
diff --git a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/DefaultFlowInfo.java b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/DefaultFlowInfo.java
index a631abc..6033483 100644
--- a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/DefaultFlowInfo.java
+++ b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/DefaultFlowInfo.java
@@ -205,6 +205,15 @@
     }
 
     /**
+     * Obtains a default flow info builder object.
+     *
+     * @return flow info builder object
+     */
+    public static Builder builder() {
+        return new DefaultBuilder();
+    }
+
+    /**
      * Builder class of DefaultFlowInfo.
      */
     public static final class DefaultBuilder implements FlowInfo.Builder {