A bug report where there is over-enthusiastic validation of content type - previous to this version, a request against an API with (for example) `application/json` would be validated as such:
* `Content-Type: application/json` would be valid
* `Content-Type: application/json; charset=UTF-8` would be invalid
Whilst arguably technically correct, we all agreed this was an unintentional over validation, and the change now allows for following directives on the Content-Type. There is no validation of the directives.
Many thanks to Rizzle93 for her patch and tests.