- Precise that 'https_only' is required when reverse proxy provides HTTPs
- Fix (again) the description of some stats entries
- Detail what admin rights do
* Untrack config.yml
`config/config.yml` has been untracked and moved to `config/config.example.yml`.
The Dockerfile has been updated to copy all `config/config.*` files and to try
to move `config/config.example.yml` to `config/config.yml`. If a user supplied
`config/config.yml` exists it is not overwritten.
* Update Dockerfile to use `shard.lock`
* Fix tests