Seed data for Demo

[juliettehutton]

• [ ] Three courses
• [ ] Five lessons for one of the courses
• [ ] The first lesson has to be complete and relevant
• [ ] In the lesson: 5 steps and their images
• [ ] 1 tutorial step, 1 multiple choice question, 1 tutorial step, 1 fill in the blank question, 1 tutorial step, 1 tutorial with a summary with finish lesson button