Support regressions history changes

bugbug/bug_snapshot.py

@@ -93,6 +93,7 @@ FIELD_TYPES = {
     'blocks': int,
     'depends_on': int,
     'regressed_by': int,
+    'regressions': int,
     'is_confirmed': bool_str,
     'is_cc_accessible': bool_str,
     'is_creator_accessible': bool_str,