Generates the migration for the workflow_instances table.
The generated migration delegates to HephaestusEcto.Migration, keeping
the table definition in the library and the migration timestamp in your app.
$ mix hephaestus_ecto.gen.migration
Options
-r,--repo— the repo to generate the migration for--migrations-path— custom migrations directory--no-compile— skip compilation--no-deps-check— skip dependency check