Improving reproducibility of notebook-generated webpages (i.e., more similar to workflowr)

[pcarbo]

We can borrow some ideas from Reproducible:

Reproducible effectively creates a one-to-one mapping between commit hashes and experimental output data.

@gaow Maybe we can return to this at some point.

Thanks to Simon Gravel for sharing.

[gaow]

Good idea and simple concept, and thanks to Simon's code we only have interface to worry about ... which is non-trivial :) we can return to the interface design later.