BasicHttpWorker should throw an exception on bad responses.

If the response code is not 200, throw an HttpBadStatusException, a subclass of HttpWorkerException that is fully contextualized by its constructor.
Ignore the output files from ant unitTests
BasicHttpWorker will require an HttpClient in the constructor.

We don't want just a vanilla HttpClient -- we want one with a longer timeout.
Also, create an HttpClientFactory so we can have one or more standard configurations of HttpClient.