Addition of 'assignments' code

So one thing that I had been thinking about was the use an 'assignments model. Essentially, the admin dashboard would include a page to select the players for the current round and create targets for each player based on who is available and who they have already targeted.

Of course, this could also be a cron job on the server to be run every monday morning. I just liked the idea of controlling what players are included in a round, and Admin control over when the round starts.

I *think* I have started this properly, but I'm still super new to ruby on rails, so.. do with it what you will.