In order to simplify the deployment of Authelia for
testing, LDAP is now optional made optional thanks
to users database stored in a file. One can update
the file manually even while Authelia is running.
With this feature the minimal configuration requires
only two components: Authelia and nginx.
The users database is obviously made for development
environments only as it prevents Authelia to be scaled
to more than one instance.
Note: Configuration has been updated. Key `ldap` has
been nested in `authentication_backend`.
Before this patch, when Authelia started, if Mongo was not
up and running, Authelia failed to connect and never retried.
Now, everytime Authelia faces a broken connection, it tries
to reconnect during the next operation.
