Update tests from Apache Commons IO 2.2 to 2.5.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/email/trunk@1744530 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 4bc21e1..63fd2e5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -247,8 +247,7 @@
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>
-            <!-- IO 2.2 is the last version compatible with 1.5; IO 2.4 needs Java 1.6 -->
-            <version>2.2</version>
+            <version>2.5</version>
             <scope>test</scope>
         </dependency>
     	<dependency>