fix mypy testing

Author: rmorshea

Diff for: setup.cfg

@@ -63,18 +63,18 @@ commands =
     nocov: pytest tests --no-cov {posargs}
     cov: pytest tests {posargs}
 
-[testenv:py38-mypy]
+[testenv:mypy]
 deps = -r requirements/mypy.txt
 commands = mypy --strict idom
 
-[testenv:py38-lint]
+[testenv:lint]
 skip_install = true
 deps = -r requirements/lint.txt
 commands =
     black . --check --exclude "idom/client/app/node_modules/.*"
     flake8 idom tests docs
 
-[testenv:py38-docs]
+[testenv:docs]
 deps = -r requirements/docs.txt
 commands =
     sphinx-build -b html docs/source docs/build