Add PatchAsync overload

[mungojam]

Is your feature request related to a problem? Please describe.
One of our APIs uses PATCH which isn't directly supported by this library.

Describe the solution you'd like
PATCH overload that would be very similar to the POST overload that already exists.

Describe alternatives you've considered
I'll use your SendAsync overload for now.

Additional context
I'll hopefully contribute more to this library in future, but lots going on at the moment. Thanks again for making it!

[FantasticFiasco]

Thanks for reporting it!

Let's see if the issue gets any traction, otherwise it eventually will be implemented. I think the implementation will be easy, but we also need to update the tests to accommodate for this new feature.

[FantasticFiasco]

Unfortunately the same argumentation as this one prevents me from working on this issue.

[mungojam]

Don't worry about it, it's not causing me a headache at all.

At some point I may implement both to help out.