Add Support for loading and Keras Model from `.h5` file

[basedrhys]

Is your feature request related to a problem? Please describe.
WDL4J contains a number of pre-loaded neural networks that can be used out of the box, however, I may have trained my own network using Keras and it would be nice to be able to load the .h5 file into WDL4J

Describe the solution you'd like
A file selector box and functionality to load a keras model from .h5 file