Documentation update

[karlaspuldaro]

Update requirements in documentation as described in #411

[bollwyvl]

This is great. We need to add this to the integrity checks!

[lresende]

@karlaspuldaro there are similar references to prerequisites on the readme that should be updated as well. Below is one example, but there are others.

You will need to have all of the following installed:

JupyterLab >=2.2.0,<3.0.0a0
Python 3.5+
nodejs 10+

[karlaspuldaro]

@bollwyvl I ran python scripts/integrity.py tests and they're all passing

[bollwyvl]

I ran python scripts/integrity.py tests and they're all passing

Right: they would, because the things you fixed ❤️ are not under test. I'm proposing we add these checks to integrity, based on the Source Of Truth for each of the items (most of which are already available in that script). Doesn't have to be on this issue, but will save frustrations in the future, as it's going to be turbulent coming up (i think lab3 needs node12, etc).

But this can be a separate issue, PR.

[bollwyvl]

at some point, in an effort to decrease the number of files in the root folder, we moved things into binder, so now the --file arg is required... conda env update has the advantage of being able to, well, update an environment, instead of just creating it.

[karlaspuldaro]

oh that makes sense now, when running the command I didn't realize it was expecting a file, or which one. Thx for clarifying :)

[bollwyvl]

also dropped this in favor of python_requires below. Of course, it's not strictly accurate, as we're still doing some unneeded song-and-dance for python 3.5, but since we don't test there anymore...

[krassowski]

Wonderful! Thank you both.

[bollwyvl]

Thanks for making time for review work!