The reason we want this is so that people do not forget to change the version number in the synapse module.
The precedent is that the version number has been 0.1.0 since the begging until now.
While this solution does mean that there may be new version of the module where
nothing has actually changed, this is still better than not changing the version at all.
Another version scheme for the module would be inconsistent to
the git repository tags and that has the potential to cause much more confusion
than "blank" version bumps.
If this is a problem, then antispam must be extracted to another repository.
In order to test this, run `yarn version --patch` observe the changes with `git log` and `git diff HEAD~`,
then YOU MUST delete the tag with `git tag --delete vd.d.d` when you are finished.
* more robust
* Move message_limit into antispam.
https://github.com/matrix-org/message_limit
Not ideal but we've had complaints about keeping them separate
and unfortunately the need for this module is not going to go away.