Feature Request: Add Gogs support

@kubiko

Gogs integration is now available as separate project: https://github.com/wekan/wekan/commit/674d45a81c94e0f862c9624b0f89743a5c675d89

It could be addition to wekan-snap like caddy is.

In general, I think that for both Docker Compose files and Snap plan is to have many additional integrations available, like Huginn, Rocket.Chat, GitLab, etc. like there is currently for wekan-mongodb and wekan-postgresql docker compose files.

For Sandstorm, integrations need to be run outside of Sandstorm using REST API, because grains are only running when someone is using them.