[DOXIATOOLS-63] Upgrade commons-io to 2.6

diff --git a/pom.xml b/pom.xml
index 0a0fbcc..94a9e36 100644
--- a/pom.xml
+++ b/pom.xml
@@ -149,7 +149,7 @@
     <dependency>
       <groupId>commons-io</groupId>
       <artifactId>commons-io</artifactId>
-      <version>2.2</version>
+      <version>2.6</version>
     </dependency>
     <dependency>
       <groupId>com.ibm.icu</groupId>