Update reqs to get tox running

setup.py

@@ -5,6 +5,7 @@ import codecs
 import os
 import re
 import sys
+
 from distutils.util import strtobool
 
 from setuptools import setup
@@ -24,6 +25,7 @@ class PyTest(TestCommand):
 
     def run_tests(self):
         import shlex
+
         import pytest
 
         errno = pytest.main(shlex.split(self.pytest_args))
@@ -38,7 +40,9 @@ def open_local(paths, mode="r", encoding="utf8"):
 
 with open_local(["sanic", "__version__.py"], encoding="latin1") as fp:
     try:
-        version = re.findall(r"^__version__ = \"([^']+)\"\r?$", fp.read(), re.M)[0]
+        version = re.findall(
+            r"^__version__ = \"([^']+)\"\r?$", fp.read(), re.M
+        )[0]
     except IndexError:
         raise RuntimeError("Unable to determine version.")
 
@@ -72,7 +76,9 @@ setup_kwargs = {
     "entry_points": {"console_scripts": ["sanic = sanic.__main__:main"]},
 }
 
-env_dependency = '; sys_platform != "win32" ' 'and implementation_name == "cpython"'
+env_dependency = (
+    '; sys_platform != "win32" ' 'and implementation_name == "cpython"'
+)
 ujson = "ujson>=1.35" + env_dependency
 uvloop = "uvloop>=0.5.3" + env_dependency
 
@@ -89,9 +95,9 @@ requirements = [
 tests_require = [
     "pytest==5.2.1",
     "multidict>=5.0,<6.0",
-    "gunicorn",
+    "gunicorn==20.0.4",
     "pytest-cov",
-    "httpcore==0.3.0",
+    "httpcore==0.11.*",
     "beautifulsoup4",
     uvloop,
     ujson,

tox.ini

@@ -7,18 +7,18 @@ setenv =
     {py36,py37,py38,py39,pyNightly}-no-ext: SANIC_NO_UJSON=1
     {py36,py37,py38,py39,pyNightly}-no-ext: SANIC_NO_UVLOOP=1
 deps =
-    coverage
+    coverage==5.3
     pytest==5.2.1
     pytest-cov
     pytest-sanic
     pytest-sugar
     pytest-benchmark
     pytest-dependency
-    httpcore==0.3.0
+    httpcore==0.11.*
     httpx==0.15.4
-    chardet<=2.3.0
+    chardet==3.*
     beautifulsoup4
-    gunicorn
+    gunicorn==20.0.4
     uvicorn
     websockets>=8.1,<9.0
 commands =
@@ -76,7 +76,7 @@ deps =
     recommonmark>=0.5.0
     docutils
     pygments
-    gunicorn
+    gunicorn==20.0.4
 
 commands =
     make docs-test