Automatically create shims after running pip install or others

[untitaker]

quickenv knows which entries have been added to PATH, it should be able to figure out which binaries to add to ~/.quickenv/bin/. Possibly this behavior should be behind a flag like quickenv reload --shim

[untitaker]

Another idea here is to suggest creating shims after commands like pip install. However, that is hard to execute on, because it requires spawning each shimmed command as subprocess instead of just execing it, because you want to run code after the command returns. So, more overhead and annoyances when trying to attach a debugger to the shimmed command.

[untitaker]

Reopening this, i saw that volta actually didn't even exec its shims, so it might be okay to just spawn a command, wait for its return and check for new shims to create.

[untitaker]

quickenv master now also adds a warning. What we can additionally do is to consider whether a pip install (where pip is shimmed), should auto-create shims for the installed binaries.