bump dependencies

Author: Kriechi

setup.py

@@ -56,6 +56,6 @@
     ],
     install_requires=[
         'hyperframe>=5.2.0,<6',
-        'hpack>=3.0.0,<4',
+        'hpack>=4.0,<5',
     ],
 )

tox.ini

@@ -14,7 +14,7 @@ passenv =
 deps =
     pytest==6.0.1
     pytest-cov==2.10.1
-    pytest-xdist==2.0.0
+    pytest-xdist==2.1.0
     hypothesis>=5.5,<6
 commands =
     pytest --cov-report=xml  --cov-report=term --cov=h2 {posargs}