Fix minor linting errors

src/wsproto/__init__.py

@@ -4,6 +4,7 @@
 
 A WebSocket implementation.
 """
+
 from typing import Generator, Optional, Union
 
 from .connection import Connection, ConnectionState, ConnectionType

src/wsproto/events.py

@@ -4,6 +4,7 @@
 
 Events that result from processing data on a WebSocket connection.
 """
+
 from abc import ABC
 from dataclasses import dataclass, field
 from typing import Generic, List, Optional, Sequence, TypeVar, Union
@@ -156,7 +157,6 @@ class RejectData(Event):
 
 @dataclass(frozen=True)
 class CloseConnection(Event):
-
     """The end of a Websocket connection, represents a closure frame.
 
     **wsproto does not automatically send a response to a close event.** To

src/wsproto/handshake.py

@@ -4,6 +4,7 @@
 
 An implementation of WebSocket handshakes.
 """
+
 from collections import deque
 from typing import (
     cast,

src/wsproto/utilities.py

@@ -4,6 +4,7 @@
 
 Utility functions that do not belong in a separate module.
 """
+
 import base64
 import hashlib
 import os