Drop support for Puppet 5 (EOL)

Author: smortex

metadata.json

@@ -33,7 +33,7 @@
   "requirements": [
     {
       "name": "puppet",
-      "version_requirement": ">= 5.5.8 < 7.0.0"
+      "version_requirement": ">= 6.1.0 < 7.0.0"
     }
   ],
   "operatingsystem_support": [