Minor edits to run code in Python 3 from volatility directory

[JohnSchwitz]

volest.py changed to: import models. It was: from volatility import models
models init.py changed to: from models.api import *

data is in tests directory thus: data_file_path = '../tests/JPM.csv'

I would add 2 explicit lines after vol. I needed to reference fig, plt not just plt.
fig, plt = vol.cones(windows=windows, quantiles=quantiles)
plt.show()

I could not get vol.term_sheet to work.

[jasonstrimpel]

Can't quite tell if these are suggestions to make compatible with Py3 or these are changes you've made. As far as the term_sheet goes, you need to ensure you define a benchmark for the regressions (included in term sheet).