We don't like updating to untagged releases, but..

0.2.1 has some regression and upstream is not releasing 0.2.2 or 0.3.0
just yet, so we either need to downgrade to 0.2.0 or go `latest`.

We can hopefully switch back to a tagged release soon.

Related to https://github.com/mautrix/instagram/issues/56

Not doing {% if matrix_admin %} checks in the YAML also fixes some issues
with indentation being incorrect sometimes.

This should be backward compatible, except for mautrix-signal's case
where `matrix_mautrix_signal_bridge_permissions` previously existed
as a string, not a dictionary. `tasks/validate_config.yml` will catch
the problem an even provide a quick fix.

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#git-latest

Our variable naming is not necessarily consistent across roles.
I've tried to follow the naming conventions of each individual role.
All new variables are suffixed with `_version`, but the prefix may be
somewhat different.

This adds https://github.com/matrix-org/matrix-doc/pull/2409 to the
appservice registrations, enabling synapse to push EDUs to appservices.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/904