Preflight Check, Twitter Auth, Build Configuration, Pick Page, Responsive Design & Markdown

Lots in this PR which I'm sure there are people rolling their eyes at.  Hey ho.

- __Twitter Authentication__ - Based on some feedback the site now uses Twitter for authentication instead of Github.  This means that people who aren;t all about code will likely be able to sign in easier (the presumption being that people will more than likely have Twitter accounts than Github accounts)
- __Preflight Check__ - Implemented the preflight check pattern to ensure that everything is in place when the app starts such as necessary environment variables.  Useful as we move down the deployment pipeline for failing early and getting quick feedback about misconfiguration.
- __Pick Page__ - The pick page is now linked and useable.  We can select items for an event and see all associated notes etc.
- __Responsive Design__ - tweaked the layout to be a bit more responsive, needs more work but it a start.
- __Chapter Request Description__ - Used to be called notes, its now description and now accepts markdown.