WIP: Populate league with default teams

@ShaiNirShado 

I'm starting with a spec to fill a new league with 22 teams (20 players, 1 commish, 1 user.). So far, so good, but I'm not sure how to add the 'type'. I may as well also add here that if I were to change Special column to Type or something of the, sort, do I just ned to change the model and then rebuild the database?

Next step after this is to apply similar methods to make 22 default teams in a league. I'm going to assume the league owner will be able to change their names as he sees fit. Do we want to use the default MLB teams here?
You can log errors here but in order for the controller function to actually return an error when team creation fails, you'd have to make the whole function into a single promise or promise chain. Does that make sense?

I would recommend looking into Sequelize's bulkCreate function so you can reduce all the teams' creation to a single Sequelize query.