Fix trigger creation during alembic migrations

sqlalchemy_continuum/transaction.py

@@ -1,4 +1,5 @@
 from datetime import datetime
+from functools import partial
 
 try:
     from collections import OrderedDict
@@ -73,10 +74,25 @@ def changed_entities(self):
 """
 
 
-def create_triggers(cls):
+def _after_create(cls, ddl):
+    """Execute DDL after a table is created
+
+    This is required for compatibility with alembic, as the `after_create` event
+    does not fire during alembic migrations"""
+    def listener(tablename, ddl, table, bind, **kw):
+        if table.name == tablename:
+            ddl(table, bind, **kw)
+
     sa.event.listen(
-        cls.__table__,
-        'after_create',
+        sa.Table,
+       'after_create',
+       partial(listener, cls.__table__.name, ddl)
+    )
+
+
+def create_triggers(cls):
+    _after_create(
+        cls,
         sa.schema.DDL(
             procedure_sql.format(
                 temporary_transaction_sql=CreateTemporaryTransactionTableSQL(),
@@ -88,9 +104,8 @@ def create_triggers(cls):
             )
         )
     )
-    sa.event.listen(
-        cls.__table__,
-        'after_create',
+    _after_create(
+        cls,
         sa.schema.DDL(str(TransactionTriggerSQL(cls)))
     )
     sa.event.listen(