Iwopy

- Small bug fixes

**Full Changelog**: [https://github.com/FraunhoferIWES/iwopy/commits/v0.1.5](https://github.com/FraunhoferIWES/iwopy/commits/v0.1.5)

- Interfaces:
- Improved: `pymoo` now supports mixed int/float problems and algorithm `MixedVariableGA`
- Changed: `pymoo`algorithms now selectable via same name as in package, i.e., GA, PSO, NSGA2, MixedVariableGA
- Examples:
- New: `mixed`, demonstrating how to solve a mixed int/float problem with pymoo
- Notebook:
- New: `mixed`, demonstrating how to solve a mixed int/float problem with pymoo

**Full Changelog**: [https://github.com/FraunhoferIWES/iwopy/commits/v0.1.4](https://github.com/FraunhoferIWES/iwopy/commits/v0.1.4)

- Core:
- Support for multi objective optimizations
- Splitting `OptResults` into `SingleObjOptResults` and `MultiObjOptResults`
- Interfaces:
- `pymoo`: Adding `nsga2`
- Examples:
- New: `multi_obj_chain`, demonstrating multi objective optimization using pymoo's NSGA2
- Notebooks:
- New: `multi_obj_chain.ipynb`, demonstrating multi objective optimization using pymoo's NSGA2

**Full Changelog**: [https://github.com/FraunhoferIWES/iwopy/commits/v0.1.3](https://github.com/FraunhoferIWES/iwopy/commits/v0.1.3)

- Tests:
- pygmo: Fixing test such that it passes on all systems

**Full Changelog**: [https://github.com/FraunhoferIWES/iwopy/commits/v0.1.2](https://github.com/FraunhoferIWES/iwopy/commits/v0.1.2)

- Tests:
- pygmo: Increased ngen and npop, intended for osx systems to pass tests

**Full Changelog**: [https://github.com/FraunhoferIWES/iwopy/commits/v0.1.1](https://github.com/FraunhoferIWES/iwopy/commits/v0.1.1)

- Bug fixes
- Updated documentation

**Full Changelog**: [https://github.com/FraunhoferIWES/iwopy/commits/v0.1.0](https://github.com/FraunhoferIWES/iwopy/commits/v0.1.0)