Check Validation of Variant Origin

[ahwagner]

I ran across 3 evidence items lacking a variant origin designation. Somehow these got past our form validation. May be worth validating at both the client and server to prevent in the future.

EIDs 6223, 6393, 6332.

[susannasiebert]

@ahwagner Do you think this should be implemented as a database constraint or via a validates_presence_of in the EI model?