Fix code style

Author: 1st1

asyncpg/prepared_stmt.py

@@ -1,5 +1,4 @@
 from . import compat
-from . import introspection
 
 
 class PreparedStatement:

tests/test_transaction.py

@@ -72,7 +72,8 @@ async def test_transaction_nested(self):
         else:
             self.fail('ZeroDivisionError was not raised')
 
-        with self.assertRaisesRegex(asyncpg.PostgresError, '"mytab" does not exist'):
+        with self.assertRaisesRegex(asyncpg.PostgresError,
+                                    '"mytab" does not exist'):
             await self.con.prepare('''
                 SELECT * FROM mytab
             ''')