Merge remote-tracking branch 'upstream/master' into azure_lint

Author: datapythonista

ci/code_checks.sh

@@ -175,7 +175,7 @@ if [[ -z "$CHECK" || "$CHECK" == "doctests" ]]; then
 
     MSG='Doctests frame.py' ; echo $MSG
     pytest -q --doctest-modules pandas/core/frame.py \
-        -k"-axes -combine -itertuples -join -nunique -pivot_table -quantile -query -reindex -reindex_axis -replace -round -set_index -stack -to_stata"
+        -k"-axes -combine -itertuples -join -nunique -pivot_table -quantile -query -reindex -reindex_axis -replace -round -set_index -stack"
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
     MSG='Doctests series.py' ; echo $MSG