Model and controller

@bsoetaer 
Test by opening irb and creating a new CLIClient.  Use start and quit to start a new game or exit the program, and select a column to play by entering the zero-based column number.
"Your “games server” must be capable of handling at least ten users on independent machines. In addition, your system should be able to support at least five servers running simultaneously on the network. The users should be divided into multiple games, where each game should run on a single server. Remember servers are virtual not physical ideas." 

Which says 10 users, 5 servers which I took as more than 1 game per server. I guess you could stretch it to mean 5 games with 2 users each.