[build] prevent race condition with CI deployed artefacts in radio
[build] prevent race condition with CI deployed artefacts in radio

There was a race condition with the continuous CI servers whereby
the CI servers were deploying versions of the generator that
were not compatible with a given verify build, but were being
downloaded by maven after the local install had occurred.

The fix is to handle the whole generate step in one reactor

Change-Id: I64b2971bf9d67fe10bdcbcc9f95cda682ef278ad

bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,clive-jevons/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,clive-jevons/joynr