Deduplicate format checking

This was being checked in both the tox tests and separately in GitHub
actions.

.github/workflows/build.yml

@@ -43,3 +43,4 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - uses: psf/black@stable
+      - uses: isort/isort-action@v1

setup.py

@@ -1,8 +1,8 @@
-from setuptools import setup, find_packages
+import re
 from codecs import open  # For a consistent encoding
 from os import path
-import re
 
+from setuptools import find_packages, setup
 
 here = path.dirname(__file__)
 

tox.ini

@@ -7,8 +7,6 @@ envlist =
     coverage_report
     py{27, 35, 36, 37}-most_platforms
     pypy{2, 3}-most_platforms
-    py39-black
-    py39-isort
 skip_missing_interpreters = true
 
 
@@ -48,26 +46,6 @@ commands =
     coverage html
 
 
-[testenv:py39-black]
-skip_install = true
-skip_build = true
-deps =
-    black
-
-commands =
-    black --check dotbot/ tests/
-
-
-[testenv:py39-isort]
-skip_install = true
-skip_build = true
-deps =
-    isort
-
-commands =
-    isort --check dotbot/ tests/
-
-
 [coverage:run]
 branch = true
 parallel = true
@@ -84,7 +62,7 @@ directory = htmlcov
 python =
     ; Run on all platforms (Linux, Mac, and Windows)
     3.8: py38-all_platforms
-    3.9: py39-all_platforms, py39-black, py39-isort
+    3.9: py39-all_platforms
     3.10: py310-all_platforms
 
     ; Run on most platforms (Linux and Mac)