Pyxirr

- Tweaked IRR to prefer rate > 0 ([24](https://github.com/Anexen/pyxirr/issues/24))
- All functions now accept date strings in the format yyyy-mm-dd or mm/dd/yyyy

- handle XIRR close to -1 (use brentq algorithm as fallback)

- Add an ability to suppress `InvalidPaymentsError` by passing `silent=True` flag ([22](https://github.com/Anexen/pyxirr/issues/22))
- Release the GIL for rust-only code
- Type hints
- Refactor tests (use `PyCFunction` interface instead of calling functions directly)
- Upgrade dependencies

- Support aarch64, armv7, s390x, ppc64le, ppc64 architectures
- Improve IRR calculation

- Wheels for python 3.10
- Add Rate, IPMT, PPMT ([18](https://github.com/Anexen/pyxirr/pull/18))
- Test against `numpy-financial` when possible

- XIRR improvements ([15](https://github.com/Anexen/pyxirr/pull/15))
- add more xirr tests
- handle XIRR close to -1
- fix nfv signature; always return None instead of nan