puppet-os-hardening 2.1.1

Implemented enhancements:

• Convert module into "standardized PDK module" #107
• Adding new param to specify maildir path. Updated nologin path for Re… #127 (hundredacres)
• converted module to pdk #107 #120 (enemarke)

Closed issues:

• net.ipv4.tcp_rfc1337 not a valid sysctl key #124

Merged pull requests:

• Add password_warn_age parameter for login.defs #128 (claw-real)
• CI: switch testing to DigitalOcean #126 (artem-sidorenko)
• Refactoring and new spec test #121 (enemarke)