Add package which name contains dot will break most things

[kukushi]

Thanks for creating such a great tool, it's really nice.

I try to add package https://github.com/yaslab/CSV.swift to my script via the marathon add. The add result show success, while I can't edit the script anymore. It keeps info me that "Failed to open script 'Balance' for editing". Then, I tried to remove the CSV.swift, although the log tells me the removal is successful, the package is still here. Finally, I have to clean up the .marathon directory to remove the CSV.swift package