Add pytest to base-env? Or other envs?

[climbfuji]

Is your feature request related to a problem? Please describe.
Do we want to add pytest to the base-env, in addition to the existing basic Python utilities? Or to other environments that require more Python packages?

Describe the solution you'd like
See above.

Additional context
Every time I want to run the ccpp-framework tests for ccpp_prebuild, I end up creating a venv and installing pytest there. As we move to adding more testing to our software environments, we should have pytest available in my opinion.

[rickgrubin-noaa]

Would like to see pytest in base-env