Split up Django Settings into DEV and PROD

[lili2311]

Description

To ensure better logging and custom setting for DEV and PROD environments we can split up django settings and setup proper logging.

1. Create a new settings folder in the london_cafes app folder
2. Make this folder a python module by creating a __init__.py file in the settings folder
3. Move all the DEV and PROD common settings into the __init__.py
4. Add dev specific setting into a development.py
5. Add proc specific settings into production.py (do not commit a key here it is secret and should be an environment variable which can be set in Heroku later on)
6. Set manage.py to call dev settings (this will be overridden in Prod by setting the env variable in Heroku)

Logging to be added in a separate issue/pr.

Example of the settings split up can be seen here

Desired Outcome

1. A new settings folder is created
2. Settings are split up into dev and proc specific settings.

[lili2311]

@denesnori I am going to unassing you but if you are keen to work on this in the next 4 weeks please ping me.