Package PyFileFixity as an AppImage for simplified installation & offline operation

[ln2max]

Having an AppImage would greatly simplify use of PyFileFixity in stressful situations ("our machines are all wiped, our data is gone, our customers are screaming, and you're telling me the backup tapes are corrupted? but you say you can fix it? WELL THEN WHY ISN'T IT FIXED YET?").

Additionally, part of protecting file archives from corruption is protecting them from malware (in particular ransomware).

Therefore, archive tasks may (and probably SHOULD) be done on an air-gapped, offline computer.

To simplify using PyFileFixity in such a scanario, having an AppImage that can be installed and used totally offline would be very useful. Right now the installation with pip3 requires an Internet connection during installation.

Generating an AppImage is relatively straightforward, there are tools for this: https://github.com/srevinsaju/pyappimage

[lrq3000]

Thank you for your suggestion and for providing a py module for this purpose, this is a good idea.

I should implement this alonside a pyinstaller binary for Windows.

Furthermore this should be automated with cibuildwheel if possible.