[Analaysis] - single command to init_db

[ErikFerrari]

• Improve mix arke_postgres.init_db in order to make it run the ecto.create, ecto.migrate, and seed the database at first starter installation.
• make mix arke_postgres.migrate to run our migration instead of writing mix ecto.migrate -r ArkePostgres.Repo

[ErikFerrari]

• init_db does not create arke_system nor create the table if the schema exists