Add license info so it is visible to maven

Change-Id: Id080103e8c43127ac4b6ffa573a75a5a03ec2db2
Reviewed-on: http://fulliautomatix.ics.uci.edu:8443/183
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <westmann@gmail.com>
diff --git a/hyracks/hyracks-storage-am-rtree/pom.xml b/hyracks/hyracks-storage-am-rtree/pom.xml
index e368081..545fa10 100644
--- a/hyracks/hyracks-storage-am-rtree/pom.xml
+++ b/hyracks/hyracks-storage-am-rtree/pom.xml
@@ -23,6 +23,15 @@
     <version>0.2.15-SNAPSHOT</version>
   </parent>
 
+  <licenses>
+    <license>
+      <name>Apache License, Version 2.0</name>
+      <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
+      <distribution>repo</distribution>
+      <comments>A business-friendly OSS license</comments>
+    </license>
+  </licenses>
+
   <build>
     <plugins>
       <plugin>