PAN-52 created the proofs DTO

persistence/scripts/mysql/local_development.sql

@@ -36,7 +36,6 @@ version int default 1
 CREATE TABLE proofs
 (
   id                       INT NOT NULL AUTO_INCREMENT,
-  username                 VARCHAR(50) NOT NULL,
   branch                   VARCHAR(512) NOT NULL,
   referenced_definitions   JSON,
   referenced_theorems      JSON,