Update from rooms to room
Update from rooms to room

`mix phoenix.new` generates a `user_socket.ex` with `room` not `rooms`.
phoenixframework/phoenix,michalmuskala/phoenix,gjaldon/phoenix,Kosmas/phoenix,0x00evil/phoenix,michalmuskala/phoenix,rafbgarcia/phoenix,dmarkow/phoenix,mobileoverlord/phoenix,mobileoverlord/phoenix,Gazler/phoenix,rafbgarcia/phoenix,jwarwick/phoenix,evax/phoenix,mschae/phoenix,trarbr/phoenix,0x00evil/phoenix,phoenixframework/phoenix,korobkov/phoenix,dmarkow/phoenix,stevedomin/phoenix,korobkov/phoenix,pap/phoenix,phoenixframework/phoenix,nshafer/phoenix,nshafer/phoenix,trarbr/phoenix,keathley/phoenix,bratsche/phoenix_guides,keathley/phoenix,jwarwick/phoenix,Joe-noh/phoenix,stevedomin/phoenix,bsmr-erlang/phoenix,eksperimental/phoenix,gjaldon/phoenix,optikfluffel/phoenix,optikfluffel/phoenix,Gazler/phoenix,eksperimental/phoenix,rafbgarcia/phoenix,mschae/phoenix,Kosmas/phoenix,evax/phoenix,pap/phoenix,optikfluffel/phoenix,mitchellhenke/phoenix,mitchellhenke/phoenix,bsmr-erlang/phoenix,0x00evil/phoenix,wsmoak/phoenix_guides,nshafer/phoenix,Joe-noh/phoenix