Add an option to force the use of gpg keys

[ozoromo]

I would love for something like vigilant mode+ being added which auto rejects any cli pushes that are not signed with a verified key.
Protected branches are not that good of an alternative since new repos will be unlocked by default and re-protecting them is tedious.

[andrea-acampora]

Github allows you to sign commit with GPG.
First, you have to generate the keys and then you have to add the -S flag in the commit.
git commit -S -m "your commit message"
You can find more info at this link