Better support for virtualenv

[montyly]

Currently all the binaries are stored in the same folder, even if a user uses virtualenv. We should detect if we are running from a virtual env, and if its the case, use a different folder.

[elopez]

I believe this has been implemented in #86

[montyly]

Mhh I see. I think the issue is that pip install solc-select is still installing 0.2.1, because 1.0 is still beta.

0.2.1 is from 2021, we should probably just do a release

[elopez]

@montyly is this still an issue?