Added join/leave game events to game service.
Added join/leave game events to game service.

cardsforhumanity/cardsforhumanity,andela/temari-cfh,andela/temari-cfh,andela/kissa-cfh-project,andela/kissa-cfh-project,andela/kiba-cfh,cardsforhumanity/cardsforhumanity,andela/kiba-cfh