back to 2017.5, for 2017.6 we need gpg GnuPG 2.1
    
    El 7 just have GnuPG 2.0 and as describe here:
    https://www.gnupg.org/faq/whats-new-in-2.1.html
    Along with the new convenience option --no-keyring it is now possible to
    encrypt data without maintaining a local keyring