Activating a virtual environment does not install requirements

[alnlarsen]

This is confusing because installed python plugins will stop working if their dependencies are not installed in the activated virtual environemnt.

We need to either

1. Automatically install requirements in the new virtual environment, or
2. Notify the user that some dependencies are missing in the new environment and ask them how they would like to proceed

[rmadsen-ks]

Actually, I am not sure we should have added support for installing requirements to begin with. They generally do not work and on some newer platforms you are not allowed to install into a global or user-local package location.

So for now I'd recommend just having the packages installed and not relying on this functionality. I dont think we will ever get this working properly.