explore TPOT package for more automated transform, feature and model selection

[realmarcin]

... this is for once we have a usable numeric matrix for analysis/ML.

The TPOT package is actually an amazing feat I think, wish they had made it sooner!
https://github.com/EpistasisLab/tpot

The notebook I committed:
https://github.com/realmarcin/biosample-analysis/blob/master/notebooks/first_analysis_notebook.ipynb

is a pipeline prototype going all the way from the original TSV (or some subset), to a numeric matrix passed to DecisionTree and viz. Lots more can be added, but this pipeline could already be plugged into TPOT.