Minor refactoring to transpile task
Minor refactoring to transpile task

- Transpiling is now gulp transpile
- Default redirects to transpile
- Refactor transpile output directory to a separate constant
- Work by @YijinL in @05ad308

chapuzzo/socket.io,Nibbler999/socket.io,l3dlp/socket.io,Automattic/socket.io,mosoft521/socket.io,l3dlp/socket.io,CxRes/socket.io,nkzawa/socket.io,gavin-lai/socket.io,kissio/kiss.io,socketio/socket.io,mosoft521/socket.io,SimenB/socket.io,DanCard0/ionic-chat-server,Automattic/socket.io,jondubois/socket.io,socketio/socket.io,datjandra/socket.io,kakalong/socket.io