Allows tests to run on java 9

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/commons/trunk@1809966 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.xml b/build.xml
index 7b6a215..9173e33 100644
--- a/build.xml
+++ b/build.xml
@@ -30,8 +30,8 @@
   <property name="javac.debug" value="on"/>
   <property name="javac.optimize" value="off"/>
   <property name="javac.deprecation" value="on"/>
-  <property name="javac.source" value="1.5"/>
-  <property name="javac.target" value="1.5"/>
+  <property name="javac.source" value="1.6"/>
+  <property name="javac.target" value="1.6"/>
   <property name="javac.fork" value="no"/>
 
   <property name="junit.fork" value="on"/>