removed ide-specific entries from gitignore
removed ide-specific entries from gitignore

Automattic/socket.io-client,ayhansalami/socket.io-client,nus-fboa2016-si/socket.io-client,socketio/socket.io-client,nkzawa/socket.io-client,Nibbler999/socket.io-client,socketio/socket.io-client,socketio/socket.io-client