debian: Use RFC2822 dates

[jgoldschrafe]

Use RFC 2822 dates for Debian Release files, as per the Debian Policy Manual:
https://www.debian.org/doc/debian-policy/ch-source.html

Closes #61.

[dnbert]

Holding off on this one until I do a new release bump, as to not break pre-existing package repos

[platinumthinker]

This don't work =(
I see for this:
W: Invalid 'Date' entry in Release file /var/lib...

I use:
Time.now.utc.strftime("%a, %d %b %Y %H:%M:%S UTC")
for convert in UTC

[mschwager]

Can we move forward with this? Ubuntu 16.04 is still complaining when installing packages without this fix.

[luksi1]

I can confirm that this works on 10.04 (lucid), 12.04 (precise), 14.04 (trusty) and fixes the Date format error on 16.04 (Xenial).

[mschwager]

I've forked this repository (https://github.com/mschwager/prm) and pulled in this commit. It's become apparent that this repository has been abandoned.