What's Changed
* File structure has changed. Now all algorithms can be imported from pymoode.algorithms and all survival classes from pymoode.survival.
* Cython files have made some crowding metrics much more efficient.
* Spacing metric has been created and can be imported from pymoode.performance.
* The library has been updated to match pymoo 0.6.* version.
* The class RankSurvival has been replaced by RankAndCrowding
* The argument 'rule' for removing individuals in survival stage has been deprecated and now is a part of the 'crowding_func'.
**Full Changelog**: https://github.com/mooscaliaproject/pymoode/compare/0.1.8...0.2.0