Add support for non-production routes

## Add support for non-production routes

### Acceptance Criteria
1. /style-guide accessible from all environments except production (use `gulp watch --env production` to simulate running in production environment).
1. Style guide will be a blank page.
1. Other routes work as they did before.

### Tasks
- Add separate method for environment-dependent routes.
- Add a style-guide page that is only accessible when not in production.


### Additional Notes
- None