Aggregations: NPE in SignificanceHeuristicStreams.read while deserializing response

[markharwood]

This is caused by the TransportClient failing to register a module that is now required to deserialize responses correctly.
The fix is to add this line to the constructor:

    modules.add(new SignificantTermsHeuristicModule());

Thanks to Felipe Hummel for reporting the error and providing a failing test case here: https://groups.google.com/forum/#!topic/elasticsearch/R42Nyyfr73I

[colings86]

I think since the SignificantTermsHeuristicModule is just for use in the Aggregations we should make TransportAggregationModule implement SpawnModules and implement the spawnModules method as follows:

    @Override
    public Iterable<? extends Module> spawnModules() {
        return ImmutableList.of(new SignificantTermsHeuristicModule());
    }