Add option to disable unique rule

[CamilleScholtz]

I'm using https://github.com/calebporzio/sushi to make my eloquent models interact with markdown files. There is no real database to speak of, as such the unique rule fails because it tries to run an SQL query. An option to disable, or to explicitly set, the unique rule would be nice.

Error in question:

SQLSTATE[HY000]: General error: 1 no such table: articles (Connection: App\Models\Article, SQL: select count(*) as aggregate from "articles" where "title" = Hoe polarisatie het vrije denken vernietigt and "articles"."id" <> hoe-polarisatie-het-vrije-denken-vernietigt)