Remove commons-io from pact-clients.

- it does not seem to be used there
- It is in conflict with commons-io from hadoop yarn (which uses commons-io 2.1)
- The coordinates of the artifact changed (and Andre and I forgot to rename it)
- My Telecom use-cases were breaking because of this: My code expected a method from commons-io:2.1 but 1.3.2 was loaded. I had no troubles loading my code with pact-client.sh, I did, however, not check if the pact webinterface still works. But eclipse did not show any errors after removing commons-io.