Add different SQL flavors

[tophcodes]

• SQLite
• MySql
• Postgres
• MSSql / SqlServer
• Access ?

Dynamically fetch the flavor by looking at the driver behind the connection.

[tophcodes]

migrate

• migrator.migrate() runs all migrations
• migrator.migrate([Migration]) runs only specific migrations
• migrator.migrate(Migration) runs only one migration

rollback

• migrator.rollback() rolls back everything
• migrator.rollback(Migration) rolls back a single migration
• migrator.rollback([Migration]) rolls back a list of migrations
• migrator.rollback(Int) rolls back a batch number

rename

• Schema.rename("from", "to")