Mccalluc/highlight codex

[mccalluc]

• Fix #60 (Or, at least enough for the Portal Cells UI work -- Another, more precise, issue can be filed if needed.)
• Fix #61

A lot of this is noise in the fixtures because the order of add_view changed... For readability, I wanted to bring together those that needed to be saved to a variable so they could be used downstream. There's a low-priority issue to sort components in the serialization to minimize this kind of noise:

• https://github.com/vitessce/vitessce-python/issues/197

[mccalluc]

@ilan-gold : I'll version bump the dependency in the portal next -- Even with that, what we see on the screen won't change, but it will support the parameterized links from the cells-ui.

[ilan-gold]

Right ok, just wanted to be sure