Refactor to RequestHandler
The "BuildRequest" method is the core of what it does
the other methods just wrap that or pass the results on the IHttpClient
It can be disentangled from the IHttpClient. This make the fluent api do more.
actually now it's more of a "Request builder" but rename comes later.
todo: fix tests
Rename RequestHandler to RequestBuilder
and get tests fixed and passing
tests around RequestBuilder probably have a lot of repetition now
Merge pull request #134 from AnthonySteele/RequestHandlerRefactor

Refactor to RequestHandler to remove IHttpClient from it