[Feature] bob erase - do not delete non empty installation_location directory

[kisuryoza]

Currently bob erase erases directories associated with bob.

When in config user sets installation_location = /home/user/.local/bin in order to have nvim among with other user's binaries, he does not expect the whole bin directory to be erased.

I suggest that after bob erase, only nvim should be deleted if the directory it is in is not empty. Or ask the user for confirmation of deleting the whole directories.

[MordechaiHadad]

@kisuryoza created a new PR, could you test it and tell me if this is what u wanted?

[kisuryoza]

No but here's what I wanted #220. I tested it with default/custom installation paths and it works as I wanted.