Update CONTRIBUTING with irc channel
Update CONTRIBUTING with irc channel

aarzilli/delve,visualfc/delve,aarzilli/delve,jeffallen/delve,sinuos/delve,jeff235255/delve,beni55/delve,lukehoban/delve,dlsniper/delve,derekparker/delve,jeffallen/delve,alexbrainman/delve,aarzilli/delve,ignatov/delve,ggndnn/delve,go-delve/delve,yigen520/delve,skyportsystems/delve,waterway/delve,aperera/delve,firebitsbr/delve,derekparker/delve,ignatov/delve,dullgiulio/delve,glycerine/delve,dr2chase/delve,go-delve/delve,lukehoban/delve,tylerb/delve,alexbrainman/delve,w4ngyi/delve,visualfc/delve,ggndnn/delve,torfuzx/delve,visualfc/delve,torfuzx/delve,alexbrainman/delve,go-delve/delve,derekparker/delve,tylerb/delve,waterway/delve,dr2chase/delve,go-delve/delve,aarzilli/delve,joeshaw/delve,aperera/delve,dr2chase/delve,jeff235255/delve,sinuos/delve,ggndnn/delve,dlsniper/delve,go-delve/delve,ironcladlou/delve,firebitsbr/delve,glycerine/delve,joeshaw/delve,beni55/delve,yigen520/delve,skyportsystems/delve,dlsniper/delve,w4ngyi/delve,ironcladlou/delve,dullgiulio/delve,ignatov/delve