Add newline to EOF
Add dev/prod config for socket server URL

Config for development and production is set by the window location. If
on AWS, then production and use herokuapp URL. If on localhost, then
development and use localhost:8888 URL. JavaScript file for socket.io is
taken from herokuapp for now.
Move socket server code to separate project

Delete server.js. Move code from client dir out into app dir as there is
no more distinction between server and client. Update references to the
modules.