Provide argument which specifies the subname of the virtual environment folder instead of automatic hashname

[tashirka1]

Hello.
It's my proposal. Assume that we in folder ~/dev/project/dummy. let's create virtual environment with command and argument pipenv shell --name=subname. It should create path ~/.local/share/virtualenvs/dummy-subname. Else it just uses old mechanism.
Thank you.

[cjw296]

@rishatsharafiev - any chance you could close this as it looks do be a dupe of #1049?

[tashirka1]

@cjw296 that's great, thank you.