Make generate_keys.sh a bit more flexible.

Allows GPG assymetrical encryption
Add Fedora as issuer and verifier
Merge pull request #7 from puiterwijk/make-generate-flexible

Make generate_keys.sh a bit more flexible.
Merge pull request #6 from puiterwijk/master

Add Fedora as issuer and verifier
Reveal level for student-vouchers
Release irma_configuration into public domain
Merge branch 'master' into pilot