Set requestBody to string.empty by default to reduce some code
Small refactor reducing a couple of lines of code
Issue #106 - Decided just to remove the comment from this field as the xml response is nullable xsi:nil="true"
Added a RequestPayload class, and added WithPayload option to FLuentApi and test, which currently does nothing
Pass request body through request builder, defaulting to key value pair if params specified
Request Body switched from string to Payload body, containing both content-type and data
THis in turn enables the content-type to be handled by the request builder, which represents this class better, as we don't really want any request manipulation i a consuming class
Refactored CheckForRequestPayload logic to a separate method
Added XMl Serializer to allow serializing of requets payload, defaulting to XML for now
Implement Entity based payloads in the fluentApi