Add translations

Created by: chrysalag

Story

https://trello.com/c/S2hGGyeM/16-as-a-developer-i-want-to-add-missing-translations

Informations

Goals

• Story is tested
• Acceptance criterias are met
• Code is reviewed
• Travis is green
• Story is on resolved in trello
• Readme is updated if needed
• Styled with Bootstrap v3
• Mobile view is usable
• Seeds are available
• German translations available