Create Node and Remove Node "Methods"

[dazinator]

Hi, thanks for this project - it seems useful!

I am using this docker image to receive the requests sent from this swarm listener: https://github.com/JanneMattila/Echo
It listens for `POST requests on /api/echo
I noticed that there are environment variables so you can set the service create and remove HTTP methods to POST (instead of GET), but I could not see in the docs the ability to set the same for create and remove nodes. Is this juts missing from the docs or does it re-use the same environment variables or something?