Pin black version

nicholas-esterer · nicholas-esterer · commit 5a7f6106a465 · 2020-10-16T12:33:26.000-04:00
diff --git a/packages/python/plotly/optional-requirements.txt b/packages/python/plotly/optional-requirements.txt
@@ -25,7 +25,7 @@ psutil
 
 ## code formatting
 pre-commit
-black
+black==19.10b0
 
 ## codegen dependencies ##
 inflect
