Dython

* Fix issues [28](https://github.com/shakedzy/dython/issues/28), [#31](https://github.com/shakedzy/dython/issues/31), [#41](https://github.com/shakedzy/dython/issues/41), [#46](https://github.com/shakedzy/dython/issues/46)
* `nominal.cramers_v` can be used without bias correction
* Removed `kwargs` from all methods, replaced with explicit API
* `nominal.associations` and `model_utils.roc_graph` now return a dictionary of output values
* `model_utils.roc_graph` can accept an `ax`
* license replaced to BSD-3

* `nominal.associations` now handles single-value features (issue [38](https://github.com/shakedzy/dython/issues/38))

* Added log-base selection in `nominal.conditional_entropy` (issue [35](https://github.com/shakedzy/dython/issues/35), by **[ahmedsalhin](https://github.com/ahmedsalhin)**)
* Added new example: `associations_mushrooms_example`
* Renamed example: `associations_example` is now `associations_iris_example`

* Requires Python 3.5+
* Private methods and attributes renamed
* Fixed incorrect `__version__` varaible

* Minor fixes
* introducing `__all__` to all modules

* `binary_roc_graph` is now a private method, only `roc_graph` is exposed