Rock Paper Scissors Tournament

Use:

  irb -rlib/tournament
  
  >> @t = Tournament.new([RockThrower, PaperThrower])
  => #<Tournament:0x5cf544 @seed=[RockThrower, PaperThrower], @players=[RockThrower, PaperThrower], @matches=[[RockThrower, PaperThrower]]>
  >> @t.run
  PLAYERS: [RockThrower, PaperThrower]
  #<PaperThrower:0x5cc790> won 100% of the time
  #<PaperThrower:0x5cc790> wins the tournament
  => #<PaperThrower:0x5cc790>
  >>