Populate csv files within a folder to populate a sport with players, part 1

@ShaiNirShado 

This one gets the most basic functionality that we're looking for. It goes through all csv files in a folder at the root called ```default_players```, then it'll go through the columns as necessary and add them to the database, and add them to the proper sport id. (Format for CSV files are written in the comments).

Next up on the list is to manipulate strings in the csv so this process isn't so troublesome where we have to manually edit all the csvs to this format, and to label rookies. 

As for the other PR, can probably safely close that one (it's mainly for review purposes), but I was wondering if we should just run this populate method when we create the new sport?
I've fixed it up so the CSV parser reads, though now it seems like it tries to find a player and fail the test before the parser is finished. Is this because I put done(); too early still? It probably has to do with the fact that the parser is asynchronous. I might see about shifting it away from async to promise like you mentioned in another comment, if that would help?