Enabling differs to be configured based on Content-Type
Added support for documents without content types
Defaulting to TextDiffer if response has no content-type
Changed content type matcher from application/json to json
Fixed bug retrieving differ for custom content type
Made header matching case insensitive for requests. Fixing issue https://github.com/realestate-com-au/pact/issues/20
Added Request.content_type method.
Updated request to use the configured differ based on the content type
Refactor method name
Ensured content-type header works in a case insensitive way when looking up the right differ
Writing tests and thoughts about text diffing
Adding ability to configure DiffFormatter based on content-type
Merge branch 'content-type-differs'