* hacking around to work out why logging and request id isnt working
* pass request id into logger so it can be structured, removed a bunch of debug logging we dont need because diagnostic trace gets it
* changed config dependency
* always have tracing available
* made it so we dont need to pass config into services.AddOcelot anymore with .net core 2.0
* add test
* lots of changes relating to logging and request ids, also updated documentation
* fixed failing test i missed
Added LogError(string) to interface as sometimes there isn't an exception
to be logged. Additionally, split Logger and LoggerFactory implementations
into seperate files just for tidiness.
Additonally added some very basic unit tests to the HttpDataRepository as
a bit of regression safety and to prove that Get never returns a null.
Slightly refactored the logic within AspDotNetLogger under
GetMessageWithOcelotRequestId so that the if statement is a little easier
to read. Attempted to remove the requestId == null, however this broke
numerous tests as the mocks don't set the behviour for dataReposioty
getting the requestId
