protoc-gen-swagger/genswagger: add PATCH support

[ericlagergren]

Fixes: #211

[ericlagergren]

CLA should be good to go (https://golang.org/CONTRIBUTORS#L340)

[achew22]

Thanks so much for sending your PR in. Do you think you could update the example protos to include a "PATCH" and regenerate the generated files? I think "make examples" is all you need to do for that.

Thanks! I look forward to having patch support.

[ericlagergren]

Yeah I think I can do it tomorrow, feel free to ping me if I forget 😄

[yugui]

@ericlagergren ping 😉

[tmc]

@ericlagergren thank you for your contribution - can you rebase and re-gen examples for this please?

[tmc]

@ericlagergren I think you are running a different version of swagger-codegen -- this project currently relies on 2.1.6

[ericlagergren]

I think you're right. I used the latest swagger-codegen release, whatever version it is. I thought the massive amount of changes looked weird, but I didn't have time to throughly debug it today.

I'll revert and re-run it with 2.16 either tonight or tomorrow morning.

[tmc]

ping @ericlagergren