Validate program data on the server when registering
Validate duration
Validate sentRegistrationEmailAddresses

Move validation after populating sentRegistrationEmailAddresses
Send 400 when invalid data
Validate sentRegistrationEmails also in reregistration
Validate email formats for classification registrationEmailAddresses
Validate duration as a proper duration string
Reorganize code and only export registration function
Merge pull request #71 from kavi-fi/registration-server-side-validation

Validate program data on the server when registering