work so far on the certificate generator
Updated schema to match previous migration
Fixed survey builder to use file attribute
Added schema API method to allow users to get survey questions
Updated survey generator code to validate fields
Whitespace tidying
Updated test certificate
Fixed duplicate response set bug
Fixed and improved generator tests
Fixed bug, which prevented repeated answers from being copied correctly
Refactored type detection to question model
Added support for repeating sections
Added authentication token to user model
Added filter to ensure authentication token is set
Added migration to give all existing users an API token
Added token authentication method and secured 
dataset submission
Added user assignment to certificate generation
Schema bump
Added simple tests for API authentication
Simplified certificate generator errors