Revert "Merge pull request #5058 from neurodebian/master"

Was mistakenly incorporated as a fix, when in reality it was a missing
skip test.

This reverts commit fd3acfdb5c0530cf78abd3c17276afc94a389d60, reversing
changes made to ec54354d8c09f0efc0811272655cb585fceadc58.
TST: Add skip test to excelwriter contextmanager
Merge pull request #5095 from jtratner/add-skip-test-excel

TST: Add skip test to excelwriter contextmanager
BUG: fix DatetimeIndex join with PeriodIndex stack overflow
TST: add test for joining PeriodIndex with DatetimeIndex