Update tests from Apache Commons IO 2.5 to 2.6.

Author: garydgregory

pom.xml

@@ -47,7 +47,7 @@ CSV files of various types.
     <dependency>
       <groupId>commons-io</groupId>
       <artifactId>commons-io</artifactId>
-      <version>2.5</version>
+      <version>2.6</version>
       <scope>test</scope>
     </dependency>
     <dependency>