Bump socket.io from 0.9.19 to 2.4.0 in /docs/test/chatrooms#2

dependabot[bot] wants to merge 1 commit intomasterbihtyu/node.js-demo:masterfrom

dependabot/npm_and_yarn/docs/test/chatrooms/socket.io-2.4.0bihtyu/node.js-demo:dependabot/npm_and_yarn/docs/test/chatrooms/socket.io-2.4.0Copy head branch name to clipboard