Add authentication, styling, and do a little refactoring

Also clean up the controller to use strong parameters. We don't ever have to split out date time parameters, as rails will automatically try to apply the composite parameters. Check out [ActiveRecord::Aggregators::ClassMethods](http://api.rubyonrails.org/classes/ActiveRecord/Aggregations/ClassMethods.html) for some info on how rails does this.

I also added pry-rails so that running `rails c` will actually open in pry.

- Use SimpleForm for resource forms.
- Use Carrierwave for image uploading.
- Cleaned up controllers and use strong parameters.
- Add validations to prevent blank events and roles.
- Add standard layout, navigation, messaging, and styling.
- Add BetterErrors for in-browser debugging.
- Add devise and require authentication to get at stuff.

- Allow roles to have the same name that belong to different events.
Yeah, I added that just so images wouldn't jump off the side of the page. I also wasn't sure how the PDF generates pictures, but it seems like we might want highest-res possible. Since it's easy enough to upload the image and see how it would look on the badge, I'm not too concerned with this limitation, but it probably shouldn't be 100% (probably want some padding or whatever).

This was just the quickest solution that didn't look terrible and didn't assume too much.