Add code linters to the project such as flake8 for Python and ESLint or Prettier the FrontEnd

[terrameijar]

To implement Continuous Integration we need to add checks and tests to the code. We need lint checks in the code to help find problems in the code syntax and to ensure that the code meets Python or JS style guides. We'll use Flake8 for Python and ESLint for Javascript. Add these to the dependencies.

Tasks:

• Add flake8 to requirements.txt in the backend. #32
• Install and add eslint to the frontend. #33