Depending on the distro, common commands like sleep and chown may either
be located in /bin or /usr/bin.

Systemd added path lookup to ExecStart in v239, allowing only the
command name to be put in unit files and not the full path as
historically required. At least Ubuntu 18.04 LTS is however still on
v237 so we should maintain portability for a while longer.

No migration steps should be required.

the changes are necessary because certbot images are tagged, so docker does not recognize the necessary architecture

Discussed in #101 (Github Issue).

Fixes #417 (Github Issue)

Fixes #330 (Github Issue).

Continuation of #234 (Github Pull Request).

I had unintentionally updated the documentation for the feature,
saying the page is available at `https://matrix.DOMAIN/nginx_status`.

Looks like it wasn't the case, going against my expectations.

I'm correcting this with this patch.
The status page is being made available on both HTTP and HTTPS.
Serving over HTTP is likely necessary for services like
Longview
(https://www.linode.com/docs/platform/longview/longview-app-for-nginx/)

We recently had someone in the support room who set it to `false`
and the playbook ran without any issues.

This currently seems to yield the same result as 'none', but it's
better to avoid such behavior.

We do use some `:latest` images by default for the following services:
- matrix-dimension
- Goofys (in the matrix-synapse role)
- matrix-bridge-appservice-irc
- matrix-bridge-appservice-discord
- matrix-bridge-mautrix-facebook
- matrix-bridge-mautrix-whatsapp

It's terribly unfortunate that those software projects don't release
anything other than `:latest`, but that's how it is for now.

Updating that software requires that users manually do `docker pull`
on the server. The playbook didn't force-repull images that it already
had.

With this patch, it starts doing so. Any image tagged `:latest` will be
force re-pulled by the playbook every time it's executed.

It should be noted that even though we ask the `docker_image` module to
force-pull, it only reports "changed" when it actually pulls something
new. This is nice, because it lets people know exactly when something
gets updated, as opposed to giving the indication that it's always
updating the images (even though it isn't).

Fixes #191 (Github Issue).

Fixes #171 (Github Issue).