Travis 3.6 Slow Build Test Failures - BS4 Issue
`test_thousands_macau_index_col` in `test_html` fails using beautifulsoup4 version 4.8.1 and passes using version 4.7.1.

Example failures:
https://travis-ci.org/pandas-dev/pandas/jobs/611742966

As pointed out by @jreback in this PR - https://github.com/pandas-dev/pandas/pull/29603

Example failing build pre my changes in #29513
https://travis-ci.org/pandas-dev/pandas/jobs/611347428

Attempting to debug issue and will report to bs4. Should we pin in the meantime to version <= 4.7.1? 
