Drop obServer Mark 1

[cvilleger]

Checklist for the first version of Drop obServer 👍

• Symfony 4
• Docker
• Tests / CI
• Basic front
• Login feature (Using OAuth 2.0 to Access Google APIs | Google Identity)
• Basic back office (to store Twitter credentials)
• Add Twitter lib/bundle
• Working Twitter engine with API endpoint (manual)
• Auto Twitter engine with backoffice
• It's ready to deliver