Mlrose

This release:
- Modifies the NeuralNetwork classes to allow the use of these classes in sklearn pipelines and GridSearchCV;
- Fixes several bugs in the algorithms which resulted in the wrong function being used to retrieve fitness values for use in the fitness curves.

This release:
* Adds a parameter to the algorithms to save the fitness scores;
* Adds a random state parameter to set the random seed for the algorithms and optimization objects;
* Adds a restart option to NeuralNetwork();
* Fixes a bug in the genetic algorithm which caused a crash when length = 1;
* Fixes a bug in the softmax function to prevent overflow.

This release corrects a bug in the MIMIC algorithm which can sometimes give rise to an infinite loop.

First stable version of mlrose, released in January 2019.