OCSADV-27: VoTableClient

This is a small PR containing VoTableClient. It uses the http commons client library to produce a method that returns a Future[CatalogProblem \/ ParsedVoResource] after making a call to one of the Gemini catalogs

A few rawtype warnings were removed as well
I’ve written this kind of code with `Future` too.  What we need is pretty simple and it does the job so I think this is probably fine to merge.

Today if I were going to write it though, I’d at least look into scalaz `Task`.  `Task` is a lot deeper and more flexible than `Future`.  It is used as an IO monad in general even if you're not interested in parallel computations.  In practical terms here it should remove the need to wrap the guts of the computation in a `fromTryCatch`.  

I don’t know though, I’m interested in what Rob would do (i.e., WWRD).  I see he didn’t do that in `TrpcClient` for example.  @tpolecat what do you think?  Just stick with `Future`?

I am a bit uneasy about `firstCompletedOf` not waiting for the second server if if the first ends with an error.  If exceptions are wrapped in a `\/` how would it know to do anything other than return the first one that finishes?