add start of docs on how to import prod DB

I wanted to add some docs on how to get production running locally, so I can properly test importing another DB. 
@bufke My preferred way is to hold all the configuration in environmental variables. I see a couple advantages of this approach over having multiple settings files. The first is that changing a configuration is painless across all platforms (dev/prod/testing). It also makes it easy to try different things. Like lets say I wanna turn on some extra logging in production, just set a env. variable. Or django-debug-toolbar. It makes configuration a lot of modular and customizable, at least in my experience [using this approach with `django-canadanewyork`](https://github.com/saulshanabrook/django-canadanewyork/blob/master/configs/settings.py). I can switch my dev environment storage backend easily, without changing any code.  It is also very transparent, allowing you to compare different environments easily.

It also provides less difference from dev to prod, which I always think is good. They always run the same python files, just with different flags set.

Plus you already are using env. variables to control a couple things, like `IS_S3` and `IS_PRODUCTION`.

This is my first time using `django-dotenv`. I find a file based solution like that helpful for development environments because it allows you to save your variables without checking them into the code. Another option is [Foreman](https://github.com/ddollar/foreman), but it is more cumbersome, requiring you to type `foreman run [command]` to get the env variables from `.env`. Or use [autoenv](https://github.com/kennethreitz/autoenv) (which I have also never used), which sources your `.env` file whenever you enter a directory. This would remove the extra dependency. Would that make more sense?

I haven't articulated my views much on this, so would appreciate anything you think I overlooked. 

I am also biased towards a [twelve factor](http://12factor.net/) way of thinking, courtesy of using Heroku predominantly.