Function diesel::migrations::mark_migrations_in_directory

pub fn mark_migrations_in_directory<Conn>(
    conn: &Conn, 
    migrations_dir: &Path
) -> Result<Vec<(Option<PathBuf>, bool)>, RunMigrationsError> where
    Conn: MigrationConnection, 

Compares migrations found in migrations_dir to those that have been applied. Returns a list of pathbufs and whether they have been applied.