[bluss]

Remove VIRTUAL_ENV from the environment when starting a new python process (new environment).

Fixes #61

First implemented by another PR, this is an alternative (maintainer's take on how to test it). Still mulling over whether this is even a desirable change.

[bluss]

Thanks to unnamed contributor who opened the other PR and prompted me to do significant cleanup (#65, #67). As always maintainership is nuanced and we need to understand the change and why/if to make it, and that's why this PR or any other for issue #61 is not merged immediately.