backend hanwatts prediction model web interface

Merge pull request #6 in UPRFIR/backend-hanwatts-prediction-model-web-interface from feature/UPRFIR-58-backend-energieverbruik-productie-opslaan-database-tests to development

* commit '546cd8b326f3106e62cd09ee1b68c3d44b5b2adc':
  single test: 100% coverage
  added  seperate tests for demonstration
  removed unused import
  100% coverage
  Typo
  100% DB test
  typo
  Added test instructions
  added test config
  added test framework