TST: register slow marker (pandas-dev#16797)

* TST: register slow marker

* Update setup.cfg

Author: TomAugspurger

doc/source/whatsnew/v0.20.3.txt

@@ -37,7 +37,7 @@ Performance Improvements
 Bug Fixes
 ~~~~~~~~~
 - Fixed issue with dataframe scatter plot for categorical data that reports incorrect column key not found when categorical data is used for plotting (:issue:`16199`)
-
+- Fixed a pytest marker failing downstream packages' tests suites (:issue:`16680`)
 
 
 

setup.cfg

@@ -22,8 +22,7 @@ split_penalty_after_opening_bracket = 1000000
 split_penalty_logical_operator = 30
 
 [tool:pytest]
-# TODO: Change all yield-based (nose-style) fixutures to pytest fixtures
-# Silencing the warning until then
 testpaths = pandas
 markers =
     single: mark a test as single cpu only
+    slow: mark a test as slow