Keplertools

This release adds an initial version of `angutils` - routines for manipulating 3D Euclidean vectors and computing various angle quantities associated with 3D rigid-body rotations.

**Full Changelog**: https://github.com/dsavransky/keplertools/compare/v1.1.2...v1.2.0

Bugfixes on new orvara-based routines.

What's Changed
* Add testing of the RV calculation based on a python implementation (which resulted in the discovery of a few bugs) by CoreySpohn in https://github.com/dsavransky/keplertools/pull/2


**Full Changelog**: https://github.com/dsavransky/keplertools/compare/v1.1.1...v1.1.2

Fixing memory leak introduced in last refactoring of C code and fixing source distribution upload to PyPI.

**Full Changelog**: https://github.com/dsavransky/keplertools/compare/v1.1.0...v1.1.1

What's Changed
* Adding orvara eccentric anomaly solver and the system RV calculations based on it by CoreySpohn in https://github.com/dsavransky/keplertools/pull/1

New Contributors
* CoreySpohn made their first contribution in https://github.com/dsavransky/keplertools/pull/1

Backend Changes
Switching to building all wheels with github CI. Cython is no longer optional and a compiler is required to build the package from source.

**Full Changelog**: https://github.com/dsavransky/keplertools/compare/v1.0.0...v1.1.0

First stable release with testing. Now with support for open orbits.

bugfix on the previous bugfix. Hopefully this one sticks.