provide `mpsd-quota` command
Provides the current use of storage for a user on /home and /scratch .
Options are available to
- display this for another user (--user USER)
- display in units of bytes (for debugging) (--bytes)
- show the version of this tool (--version)
- show some additional output (--verbose)
Tests are minimal and pass when run on an HPC node.
[I plan to add continuous integration and a few more tests later.]