Add oparent version as a property

We refer to oparent in other pom.xml in the policy projects. This
is to ensure we are always referring to the same version.

Issue-ID: POLICY-1073
Change-Id: Ie09cdb76f3fe181cc55df2d0fa8833cba382cf46
Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>
diff --git a/pom.xml b/pom.xml
index 0370bb5..fb5b940 100644
--- a/pom.xml
+++ b/pom.xml
@@ -30,6 +30,9 @@
     <version>2.0.0-SNAPSHOT</version>
     <packaging>pom</packaging>
 
+    <properties>
+        <oparent.version>1.1.0</oparent.version>
+    </properties>
 
     <modules>
         <module>integration</module>