Read the Docs Environment Build Crashing

[catherine-martlin]

New updates to the environment-3.7.yml and the pip_requirements.txt have made RtDs freak out when trying to install the environment to build the docs. I tested an update in PR #413 that re-aligns some of the packages so they're the same version and RtDs builds successfully again.

@bourque can we chat about these packages and check if having them match is okay for the rest of ExoCTK? If they have to be different I'll need to update RtDs to build its environment differently so it doesn't get angry and stuck in a weird install/uninstall loop.