Added Heirarchical prior.

[meetdoshi90]

Added path smoothing to prevent overfitting for deeper trees whilst improving accuracy. Added mse loss for regression on weighted layers. References:

1. Path smoothing
2. IHT Gradient descent

[ghost]

All CLA requirements met.

[adityakusupati]

hi @meetdoshi90,

This is very useful and seems correct. Thanks for the contribution. However, I think the TF bonsai version is obsolete due to its old dependencies. I think more people use the pytorch version more often.

@harsha-simhadri you might want to take a look at this when you get a chance.

Aditya

[meetdoshi90]

Hey @adityakusupati I will implement the same on pytorch. Thanks for the advice. Meet.