Generates a migration that creates the etcher_annotations table used by
Etcher.Storage.Default.
mix etcher.gen.migrationThe migration is written into the consumer's priv/repo/migrations/
directory with a timestamped filename, just like mix ecto.gen.migration.
Options
-r,--repo— the Repo module to target. Defaults to the first repo in your Mix project's:ecto_reposconfig.
After running
mix ecto.migrateConsumers who roll their own annotation schema can skip this generator
entirely and implement the Etcher.Storage behaviour against their own
table.