Workflow follow-up

[wlandau]

This PR follows up on #6:

• Convert the rendered HTML of workflow/tensorflow-drake.Rmd back to notebook form.
• Update images/dep-graph.png.
• Remove superfluous files such as workflow/newmodel/.

After this, I think it just remains to refresh the notebook at colorado.rstudio.com.

[edgararuiz-zz]

Awesome job, thank you

I just updated the notebook, please let me know if that looks ok to you: https://colorado.rstudio.com/rsc/content/2159/tensorflow-drake.nb.html

[wlandau]

Thanks, @edgararuiz! I think the notebook rendered well, and I proposed a couple minor updates in #8.

Regarding richfitz/storr#77 (comment), storr, and serialization in general (particularly if there is a way to avoid serialization while still being able to store and hash arbitrary data) I would love advice if you have the time. I think your expertise could really help speed up drake.