Update Cymetric CI

[bennibbelink]

• adds GitHub workflows and removes circleCI
• converts nosetests to pytest
• includes the changes from Fix pandas, collections, imp warnings #185

[bennibbelink]

Also updated the README, setup.py, and added a pyproject.toml to completely address #186

[bennibbelink]

When we eventually push a new cyclus python package, we should add it as a required dependency in pyproject.toml

[gonuke]

Thanks @bennibbelink - this looks like a lot of tedious changes. There are a lot of strange whitespace changes, too.

Looks as though you may be changing some things as I review... but here are a few comments.

[gonuke]

shouldn't this depend on whether we are apt or conda? Or we should install it a dependency back when cyclus builds?

[bennibbelink]

For now I added another step in the workflow. Eventually in cyclus we should use the python -m pip install method to install cyclus instead of just calling setup.py directly, so we will need pip as a dependency anyway

[bennibbelink]

I've implemented this in a branch of cyclus that I have, along with some updates to the cmake build. I stumbled along some fixes while trying to get cython working, but I can make a separate PR for these general build changes

[gonuke]

One of these days we should make this an action we can reuse across projects.

[gonuke]

more whitespace differences making this hard to review

[bennibbelink]

If you click the settings icon you can choose to hide whitespace. This seems to work for me, it is easier to read changes

[gonuke]

Yeah - I remembered that... but still confused by all the phantom whitespace changes.