feat: add tox configuration

tox.ini

@@ -0,0 +1,51 @@
+[tox]
+min_version = 4.4.0
+envlist =
+    format
+    lint
+    coverage
+    py38
+    py39
+    py310
+    py311
+    py312
+    pypy3
+
+[testenv:test]
+description = run the distribution tests
+use_develop = true
+skip_install = false
+constrain_package_deps = true
+commands =
+    pytest run_tests.py
+extras =
+    test
+
+[testenv:format]
+description = automatically reformat code
+skip_install = true
+deps =
+    pre-commit
+commands =
+    pre-commit run -a pyupgrade
+    pre-commit run -a isort
+    pre-commit run -a black
+
+[testenv:lint]
+description = run linters that will help improve the code style
+skip_install = true
+deps =
+    pre-commit
+commands =
+    pre-commit run -a
+
+[testenv:coverage]
+description = get a test coverage report
+use_develop = true
+skip_install = false
+deps =
+    coverage
+commands =
+    pytest run_tests.py --cov --cov-report term-missing
+extras =
+    test