BUG: Timestamp == date match stdlib
- [ ] closes #xxxx
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

ATM we have one reasonable behavior `Timestamp("2020-09-04") == date(2020, 9, 4)` and two un-reasonable behaviors: ``Timestamp("2020-09-04").tz_localize("US/Pacific") == date(2020, 9, 4)`, `Timestamp.now() == Timestamp.now().date()`.  Since the stdlib datetime doesnt consider `datetime(2020, 9, 4) == date(2020, 9, 4)`, this follows the stdlib and considers them never equal.

<s>I'm still getting one test failure locally.</s>

cc @mroeschke 