api/strip: implement the http client side
pkg: we are now only py3
Added tag 0.7.3 for changeset 1a69182a9b04
dates: do not crash when presented with a stdlib datetime object
highlight the fact that we do not handle plain datetime objects

Which is un-nice.
api/insert: document the assertion failure

If a bad api url was provided it might show up there.
Added tag 0.7.2 for changeset 2235e4657f1a
doc: small corrections
fix crash with non-utc border dates

Everything is converted to utc before requesting.
test/dates: exhibit a crash condition (using non-utc tzaware border dates)
Added tag 0.7.1 for changeset 728ccc83ca43
register-formula: in the success path, do not return anything
test/get+revdate: show that we do not crash

This needs tshistory > 0.12.1
test: add a test with get + revision date
update/replace: make sure we get back the diff

Not doing so is an api violation.
Added tag 0.7.0 for changeset d701d7365524
test/formula-components: adjust for late minute tshistory-formula api change