Lemmy.ml `v0.19` upgrade issues and downtime.

In anticipation of Lemmy's upcoming 0.19 release, and to work out any final issues, we're going to deploy a test release on lemmy.ml within the next few days.

We're doing this testing on lemmy.ml only, so that we can encounter any issues before the release, and to make sure the upgrade process is smooth for other production servers.

Some of the following will happen during the process:

• Apps will likely break (only for lemmy.ml)
• Lemmy.ml may experience some downtime for the upgrade to complete (ideally no more than an hour).
• If anything goes wrong, we may have to restore from a database backup, meaning content made in between backups may be lost.

If all goes well, we'll have an official announcement for the release after this testing period.

I apologize for the difficulties this might cause. At most this will be a week of hair-pulling, but its vital that we catch any issues before telling other servers to upgrade.