Add AUTO_SCHEMA_UPGRADE toggle

app/config.py

@@ -59,6 +59,10 @@ class Config:
     # stream straight to disk and never go through Flask's form parser.
     BACKUP_MAX_UPLOAD = int(os.environ.get('BACKUP_MAX_UPLOAD', 0))
 
+    # Add missing columns automatically at startup. Turn off if you'd
+    # rather manage schema changes with Flask-Migrate yourself.
+    AUTO_SCHEMA_UPGRADE = os.environ.get('AUTO_SCHEMA_UPGRADE', '1') != '0'
+
     # Pagination
     SETS_PER_PAGE = int(os.environ.get('SETS_PER_PAGE', 20))