update tox

tox.ini

@@ -1,53 +1,38 @@
 [tox]
-envlist = py37, py38, py39, coverage, flake8, pylint
-
-[gh-actions]
-python =
-    3.7: py37, coverage, flake8, pylint
-    3.8: py38, coverage, flake8, pylint
-    3.9: py39, coverage, flake8, pylint
+envlist = lint, py3{7,8,9}, pypy3, coverage-report
+skip_missing_interpreters = true
 
 [testenv]
 deps =
-    pytest
-    coverage
     -r requirements.txt
-commands = coverage run -m pytest {posargs}
+    -r test_requirements.txt
+; download the latest pip, setuptools and wheel when creating the venv
+download = true
+commands =
+    coverage run --parallel-mode -m pytest {posargs}
 
-[testenv:coverage]
-deps = coverage
+[testenv:lint]
+skip_install = true
+deps =
+    -r test_requirements.txt
+commands =
+    black --check --diff .
+    isort --check-only --diff .
+    flake8
+
+[testenv:coverage-report]
 skip_install = true
 commands =
+    coverage combine
+    coverage xml
     coverage report
     coverage html
 
-[testenv:flake8]
-deps =
-    flake8
-commands = flake8 --count --show-source --statistics
-
-[testenv:pylint]
-deps =
-    pylint
-wont_fix = invalid-name,protected-access,too-many-lines
-maybe_someday = fixme,missing-docstring,line-too-long
-commands = pylint --disable={[testenv:pylint]wont_fix},{[testenv:pylint]maybe_someday} --ignore=axes_pb2.py Lib/axisregistry
-
 [flake8]
-select = E,F,W
+select = C, E, F, W, B, B9
+ignore = E203, E266, E501, W503
+max-line-length = 88
+exclude = .git, __pycache__, build, dist, .eggs, .tox, venv, venv*, .venv, .venv*
 
-exclude =
-# Exclude the entire build directory:
-    build
-# Exclude these auto-generated files that should not be hand-edited:
-    Lib/axisregistry/*_pb2.py,
-# No need to traverse hidden directories such as .git, .tox
-    .*,
-# Exclude virtual environment directory:
-    venv*,
-# There's no value in checking cache directories
-    __pycache__,
-
-max-line-length=100
-ignore = 
-    E126, # continuation line over-indented for hanging indent
+[isort]
+profile = black