commons-io:2.6

[jburel]

From https://trello.com/c/BlGHuLuD/159-commons-io26

cF: https://idr-ci.openmicroscopy.org/jenkins/job/OMERO-build/3/

During the setup of both latest-ci and idr-ci, the OMERO-build job initially and consistently fails with:

09:09:26 retrieve:
09:09:26 :: Apache Ivy 2.4.0 - 20141213170938 :: http://ant.apache.org/ivy/ ::
09:09:26 :: loading settings :: file = /home/omero/workspace/OMERO-build/src/etc/ivysettings.xml
09:15:21 :: problems summary ::
09:15:21 :::: WARNINGS
09:15:21 		[NOT FOUND  ] commons-io#commons-io;2.6!commons-io.jar (0ms)
09:15:21 	==== user-maven: tried
09:15:21 	  /home/omero/.m2/repository/commons-io/commons-io/2.6/commons-io-2.6.jar
09:15:21 		::::::::::::::::::::::::::::::::::::::::::::::
09:15:21 		::              FAILED DOWNLOADS            ::
09:15:21 		:: ^ see resolution messages for details  ^ ::
09:15:21 		::::::::::::::::::::::::::::::::::::::::::::::
09:15:21 		:: commons-io#commons-io;2.6!commons-io.jar
09:15:21 		::::::::::::::::::::::::::::::::::::::::::::::

until the slave/.m2 directory from merge-ci is rsync'd over.