WIP: Dockerize databases to speed-up local testing

[jsau-]

Adds Docker containers for supported database types to speed up testing.

Relates to: https://github.com/sequelize/sequelize-auto/issues/478

Outstanding issues: On boot the mssql container complains about errors, seems that the model script might have problems?

[steveschmitt]

@jsau- I updated the mssql scripts in sample/dbscripts (in the master branch). See if those changes help you.

[jsau-]

Awesome, thanks, I just took a quick look and I'm still getting the same error. I should have some time this weekend to properly look at it - it'll likely be something wrong with what I'm doing; I ran everything from master manually in an mssql shell and they all seemed to execute fine without issue.