Changed AssayResult.assay_result, AssayResult.result_function, and AssayResult.result_type to allow null and blank to avoid errors in migrations.
Changed AssayResult.assay_result, AssayResult.result_function, and AssayResult.result_type to allow null and blank to avoid errors in migrations.

UPDDI/mps-database-server,UPDDI/mps-database-server,UPDDI/mps-database-server,UPDDI/mps-database-server