Fix puppet version for requirements in metadata

http://logs.openstack.org/08/393008/1/check/gate-puppet-openstack-integration-4-scenario002-tempest-ubuntu-xenial/283f87f/logs/puppet-version.txt.gz

Change-Id: I356613a64b99c5e57e211fd1f24e2e484a8cc05b

metadata.json

@@ -10,11 +10,11 @@
   "requirements": [
     {
       "name": "pe",
-      "version_requirement": "3.x"
+      "version_requirement": "4.x"
     },
     {
       "name": "puppet",
-      "version_requirement": "3.x"
+      "version_requirement": "4.x"
     }
   ],
   "operatingsystem_support": [