Added support for the optional game ID in server info
Added support for the optional game ID in server info

Although this is (almost?) always equal to the application ID it
might be useful in the future.

bfosberry/steam-condenser-ruby,kickback/steam-condenser-ruby,koraktor/steam-condenser-ruby,hcool/steam-condenser-ruby,Arie/steam-condenser-ruby,jpalumickas/steam-condenser-ruby