Merge pull request #5 from kezabelle/feature/test_docs

Add brief documentation on how to run tests
unit test the expectations for getting the querystring from a request.
tests for urlencoded form data
test for when the request content type wasn’t something to be handled via request_data
unit test for MethodNotAllowed responses; fixes `TypeError: 'MethodNotAllowed' object does not support item assignment`
unit tests for using the LocationHeaderMixin subclasses successfully.
Fixes: TypeError: 'MovedPermanently' object does not support item assignment
Fixes: AttributeError: 'MovedPermanently' object has no attribute 'allowed_schemes'
unit tests for branch coverage for status code/message
unit test for the simple add_cookie branch.