Brooklyn 20 apache rat

This resolved BROOKLYN-20

Note, this is dependent upon https://github.com/apache/incubator-brooklyn/pull/43
@aledsage agreed. However that should not stop us merging this PR, which is designed to stop any future infractions before they even become PRs. There are known cases in the current code where we have license compliance issues so we should deal with `couch.uri` and other suspicious exclusions at that time.