Use older 'isort' version

lukelbd · lukelbd · commit 8e0cabc08adb · 2020-07-09T12:03:31.000-06:00
diff --git a/ci/environment.yml b/ci/environment.yml
@@ -20,7 +20,7 @@ dependencies:
   - pip:
     - ..
     - flake8
-    - isort
+    - isort==4.3.21
     - doc8
     - pytest
     - pytest-sugar
