Installs Squid Mesh by creating its migration in the host application.
Usage
$ mix squid_mesh.install
This task creates one current-schema Squid Mesh migration in
priv/repo/migrations so the host application can run it through its normal
Ecto migration flow.
Executor-specific migrations are intentionally not copied. Squid Mesh assumes the host application owns the queueing backend used by its executor.