Create tutorial for 3d regression.

[paul-reiners]

I'm always frustrated when deep learning libraries (or books on deep learning libraries) have an example for classification but not regression. I realize that for the experienced user, it's easy to modify a classification example to regression, but for the inexperienced user, this can be difficult without a concrete example.

I will create a 3D regression tutorial very similar to the 3D classification tutorial. I will have to find a real-valued and continuous feature, and I will probably need to use a different publicly available data set.

A possible alternative would be to put commented code in the classification example, showing how to transform it into a regression example. These comments could be unwieldy and distracting, particularly if you use a different data set.