Way to spell TimeDelta::MIN on older chrono versions

[ngoldbaum]

Over at PyO3/pyo3#4785 we're confused about how to update a test that uses min_value to not emit a deprecation warning on the newest chrono version but still be runnable on our minimum supported version. The suggestion in the deprecation message is only possible on the latest version of chrono.

[djc]

Why do you have an older minimum version of chrono?

[ngoldbaum]

We only use min_value() in a test, so it seems wrong to bump the minimum required version to fix a test. Would you just bump the minimum chrono version in PyO3's Cargo.toml for the chrono feature?

[djc]

Yes, it doesn't seem like a big deal. Could go with 0.4.38 if that's new enough since 0.4.39 is relatively recent. Or just suppress the warning about deprecation in your test.

[ngoldbaum]

Cool, we'll just do [allow(deprecated)] I think. Thanks for the advice!