adding staging repository before release

Change-Id: I49123dcca6c104e6d7ad7b3d3a30d75dc01f1082

@@ -30,6 +30,15 @@
         <relativePath>tools/build/pom.xml</relativePath>
     </parent>
     
+    <!-- FIXME remove before release -->
+    <repositories>
+        <repository>
+            <id>oss-staging</id>
+            <name>OSS Staging</name>
+            <url>https://oss.sonatype.org/content/groups/staging</url>
+        </repository>
+    </repositories>
+
     <groupId>org.onosproject</groupId>
     <artifactId>onos</artifactId>
     <packaging>pom</packaging>