Pyheadtail

**Changes**
- Compatibility with cython 3.0

**Full Changelog**: https://github.com/PyCOMPLETE/PyHEADTAIL/compare/v1.16.0...v1.16.1

- Optimization of wake tables giving significant speed-up
- Add a new set of simulation examples and simulation-based tests with numerical checks
- Remove unused modules and remaining deprecated syntax after Python 3 migration

- Add LongSpaceChargeRectPipe class
- Change release and versioning method
- Several improvements in GPU support
- General package cleanup

**Fixes:**
- Small changes in the documentation.

**This version is incompatible with Python 2!**

**New features:**
- Migration to Python 3
- Documentation and small fixes in synchrotron module
- Sphinx auto-generated documentation available at http://pycomplete.github.io/PyHEADTAIL/

**This version of PyHEADTAIL is incompatible with Python 2!**


v1.13.5_python3
**Python 3 version of [PyHEADTAIL v1.13.5](https://github.com/PyCOMPLETE/PyHEADTAIL/releases/tag/v1.13.5).**

**This version of PyHEADTAIL is incompatible with Python 2.**

Hotfix:
- fixing issue https://github.com/PyCOMPLETE/PyHEADTAIL/issues/102 with NaN emittances when the beam has a zero-filled array in `dp`. Addresses both GPU and CPU implementations, as well as bunch emittance and slice emittance functions.