FEAT: Enable Live Action for `ipywidgets` (using `thebe`)

[mmcky]

There are two lectures that contain ipywidgets that need to be updated to show the figure some how

• matsuyama
• black_litterman

[mmcky]

A short term fix is proposed in #32

[mmcky]

These objects now render in the v0.2+ of the quantecon-book-theme. We should however experiment with enabling thebe to let them become interactive.