Include a pointer to the Site Configuration file
Add to the HadoopContextHelper: read an XML file.
Use the parsed SiteConfig in discovery.
Isolate the details of HttpClient behind an interface.

This will likely have additional methods. It makes it easy to write unit tests where we force the result of the HTTP call.
A first attempt at discovery on a VIVO site.
Unit tests and test tools
A live test that runs outside of Hadoop.