Merge pull request #53 from andreoliw/feature/update-requirements

{{cookiecutter.app_name}}/requirements/dev.txt

{{cookiecutter.app_name}}/requirements/prod.txt

...iecutter.app_name}}/{{cookiecutter.app_name}}/database.py

...iecutter.app_name}}/{{cookiecutter.app_name}}/settings.py

...r.app_name}}/{{cookiecutter.app_name}}/templates/nav.html