Add API for get and set sensor values

[tisljaricleo]

• The goal: create API for getting and setting values of the sensor model using the HTTP requests
• This will be used by Arduino (ESP32 board) to send sensor values data to the server
• Django rest framework documentation https://www.django-rest-framework.org/
• Good tutorial https://medium.com/swlh/build-your-first-rest-api-with-django-rest-framework-e394e39a482c
• After coding run flake8 test