moved commons-pool to root pom.xml

Change-Id: Ic366fd4c790d6a9b9c43d6b593e034427eefa6a6
diff --git a/pom.xml b/pom.xml
index 56bbd74..cb00f32 100644
--- a/pom.xml
+++ b/pom.xml
@@ -248,6 +248,11 @@
                 <classifier>tests</classifier>
                 <scope>test</scope>
             </dependency>
+            <dependency>
+              <groupId>commons-pool</groupId>
+              <artifactId>commons-pool</artifactId>
+              <version>1.6</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>