Support puppet 7

Author: deric

.fixtures.yml

@@ -4,7 +4,9 @@ fixtures:
     apt: "https://github.com/puppetlabs/puppetlabs-apt.git"
     augeas_core: "https://github.com/puppetlabs/puppetlabs-augeas_core.git"
     concat: "https://github.com/puppetlabs/puppetlabs-concat.git"
-    cron_core: "https://github.com/puppetlabs/puppetlabs-cron_core.git"
+    cron_core:
+      repo: "https://github.com/puppetlabs/puppetlabs-cron_core.git"
+      ref: "170dce752d994d0eb375b941b9c9c83e2c6eb949"
     facts: 'https://github.com/puppetlabs/puppetlabs-facts.git'
     firewall: "https://github.com/puppetlabs/puppetlabs-firewall.git"
     provision: "https://github.com/puppetlabs/provision.git"