Seperating Settings and securing db-pass and security-tokens

[emrehayirci]

After creating DockerFile we saw some improvements can be made to make things right:

• Settings should be seperated from debugging settings like https://stackoverflow.com/questions/10664244/django-how-to-manage-development-and-production-settings
• Seperate security credentials to external credentials.py file and adding it to .gitignore
• To make this repo more contributer-friendly use sqlite at development and postgre at production (I know that we might encounter some problems about compatibility. Some features might not work as expected sqlite than it works at postgre but making this repo contributer friendly is our top priority)
• Create a guide about how to run server for development and production
• Change dockerfile to use Gunicorn

[emrehayirci]

This is still a thing that @mertcangurcan would be interested in