Fix bad OS mapping in installation script

[rnealson]

This Fixes #442

I also added a SUCCESSFUL flag and a condition to keep temp files if an install failed.

[jsoverson]

Thanks @rnealson. The failing check is due to the commit linter. We use conventional commit style and that check ensures it. You can amend your commit with git commit --amend to something like fix: fixes #442 or LMK and I can do it.

[rnealson]

Fixed the commit

[jsoverson]

Thanks @rnealson!