We use an unmaintained package called `activitystrea.ms` for the
activity pub middleware. Since the activity pub middleware is dead code
at the moment I suggest that we remove that package and disable all the
code that depends on the package.
When we get back to implement the ActivityPub spec for Human Connection I
would suggest to maintain this package `activitystrea.ms`, update the
dependencies there and re-enable and **test** the code of the activity pub
middleware.
This commit takes all backend changes for signup and invite feature. I
was working on these features and removed the generated mutations for
type user along the way.
