Fix flake8.

.github/workflows/everything.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
         os: [macOS, Ubuntu]
 
     steps:

hiyori/http_client.py

@@ -27,6 +27,7 @@
 )
 import asyncio
 import collections
+import dataclasses
 import re
 import ssl
 import urllib.parse
@@ -64,6 +65,7 @@
 ]
 
 
+@dataclasses.dataclass
 class _ReadLock:
     def __init__(self, client_lock: "_ClientLock") -> None:
         self._idling = asyncio.Event()
@@ -88,6 +90,7 @@ async def __aexit__(self, *args: Any, **kwargs: Any) -> None:
             self._idling.set()
 
 
+@dataclasses.dataclass
 class _CloseLock:
     def __init__(self, client_lock: "_ClientLock") -> None:
         self._closing = False
@@ -103,6 +106,7 @@ async def __aexit__(self, *args: Any, **kwargs: Any) -> None:
         pass
 
 
+@dataclasses.dataclass
 class _ClientLock:
     def __init__(self) -> None:
         self.read_lock = _ReadLock(self)

pyproject.toml

@@ -24,7 +24,7 @@ classifiers=[
 include=["hiyori/py.typed"]
 
 [tool.poetry.dependencies]
-python = "^3.6.1"
+python = "^3.7.1"
 importlib-metadata = { version = "^4.0.1", python = "<=3.7" }
 
 # Http