Unpin tox dependencies

This allows the checks to be made against the latest versions thereby
ensuring the most up to date and useful checks.

Author: pgjones

tox.ini

@@ -13,9 +13,9 @@ python =
 passenv =
     GITHUB_*
 deps =
-    pytest>=6.1.2,<7
-    pytest-cov>=2.10.1,<3
-    pytest-xdist>=2.2.1,<3
+    pytest
+    pytest-cov
+    pytest-xdist
 commands =
     pytest --cov-report=xml --cov-report=term --cov=wsproto {posargs}
 
@@ -25,10 +25,10 @@ commands = pytest {posargs}
 
 [testenv:lint]
 deps =
-    flake8>=3.9.1,<4
-    black>=22.1.0,<23
-    isort==5.10.1
-    mypy==0.931
+    flake8
+    black
+    isort
+    mypy
     {[testenv]deps}
 commands =
     flake8 src/ test/
@@ -38,7 +38,7 @@ commands =
 
 [testenv:docs]
 deps =
-    sphinx>=4.0.2,<5
+    sphinx
 whitelist_externals = make
 changedir = {toxinidir}/docs
 commands =
@@ -48,9 +48,9 @@ commands =
 [testenv:packaging]
 basepython = python3.10
 deps =
-    check-manifest==0.46
-    readme-renderer==29.0
-    twine>=3.4.1,<4
+    check-manifest
+    readme-renderer
+    twine
 whitelist_externals = rm
 commands =
     rm -rf dist/