CLN: make chunksize an integer in  to_csv to avoid float slicing semantics
CLN: make nxes integers in _get_layout
Merge pull request #7204 from jreback/depr_clean

CLN: eliminate depr warnings on 3.4
BUG: check edge case with GH7190
COMPAT: disable Series datetimeindex/periodindex methods introduced in (GH6380)
DOC: changes to remove Series datetime-like properties (GH6380)
Merge pull request #7206 from jreback/ops

API: remove datetime-like index ops from Series
ENH: Add dateutil timezone support GH4688

Adds support for dateutil timezones across pandas.
Support conversion between dateutil and pytz timezones.
Ensure timezone functionality is tested with both dateutil and pytz.