Support PATCH as a valid HttpOption method

Currently the supported methods for HttpOptions are: 'DELETE' | 'GET' | 'HEAD' | 'POST' | 'PUT', however PATCH and OPTIONS are also a valid methods and it would be nice if the the method field in HttpOptions supported them. Right now I'm getting around the problem by simply bypassing the typing with method: <any>'PATCH'.

You're right those should be added. I'd accept a PR if you want to add that to the types.