Refactored sections and some fixes.
- Re-work memory ownership model by claudioperez in https://github.com/claudioperez/OpenSeesRT/pull/37
- Correct term in shell corotational formulation
- Implement OpenSeesPy section interface
- Remove `Fiber` class
- Refactor fiber sections
**Full Changelog**: https://github.com/claudioperez/OpenSeesRT/compare/initial-zenodo...0.0.58
initial-zenodo
First Zenodo release.