Fixed typos in posts.js that prevented compile
Fixed formatting of Discover view and header.ejs
Added socket.io to package.json
Fixed errors in app.js

-Several typos were fixed that caused the app to not compile
-The variable 'post' = require(./lib/posts) has been renamed 'posts' so as not to confuse it with the route 'post'
-The port on which socket.io listens must be a different port from APP_PORT, or else it won't compile