* copy-paste the description from schema.rb,
* without the `force: :cascade` options (that drops the tables before recreating them).
* create a new migration with it
* give it the same timestamp as the last deleted migration, so that it exists in the schema_migration table and it is not run in production.
* (Also got rid of some stray changes in schema.rb for mon_avis and unconfirmed_email)
* Run rake db:migrate and make sure nothing moves
