February updates

poliastro finally landed support for Python 3.9, thanks to the fine folks of numba! Their release candidate already works with the newest Python release, and we've been told that the stable release is around the corner. This means that the next stable release of poliastro will also support it 🚀

On the validation side, Jorge has been working on more enhancements, and we have finally confirmed that our 3D impulsive maneuvers give the same result as GMAT and Orekit! You can read the full details in this blog post.

And finally, we have made some small improvements on the development side, by fixing some continuous integration small failures, reducing the number of warnings in our tests, and other small fixes. Thanks Yash, Dhruv, zkl2, and Souhit!