Request: add support for deflate encoding

[aharpervc]

Hi, I've started playing with restish, very cool project!

My request is to add support for deflate encoding. I see by default the accept-encoding header is br,gzip but I'm working with an API that only supports deflate.

I confirmed that I can override that header with a persistent header in my config file, but that results in an error: Caught error: unsupported content-encoding deflate

[aharpervc]

Hi, thanks for adding this feature. I've now been able to revisit restish since you added it. I noticed that with my API, the response body is no longer printed when the response is deflate encoded. I can add --rsh-header 'accept-encoding:identity' and the response body is printed as normal. With --rsh-verbose, I see various ascii codes dumped out with <?>'s, I'm guessing that's the raw response, and DEBUG: Decoding response from deflate. No errors are indicated.

Is this expected? Can restish be configured to show the response body after decompression?

[aharpervc]

@danielgtaylor thoughts?