gitmate YAML configuration

[jayvdb]

gitmate configuration is stored in the webapp, not in the repository.

This has zero transparency and reduces the ability for newcomers to learn the system.

This is a medium complexity project, as all existing gitmate plugin configuration needs to be supported, and it needs to be extensible to support new plugins as well.

[jayvdb]

A stretch goal for this would be specifying custom plugins in the YAML, which might be loaded from the repository or some other source. The gitmate service would need a whitelist or similar to prevent loading in malicious plugins.

[jayvdb]

c.f. #488

[jayvdb]

An important aspect of this project is that when combined with moban, it will allow all coala repos to have similar settings. c.f. coala/coala#4897

[jayvdb]

See https://gitlab.com/gitmate/GitMate-2-ideas/issues/31 and https://gitlab.com/gitmate/open-source/gitmate-2/issues/363

[jayvdb]

https://github.com/rtfd/readthedocs.org/milestone/28 is a similar GSoC for readthedocs.