Fix stdlib and Puppet version requirements in metadata.json

Official stdlib docs state that stdlib 2.x is not compatible with
Puppet 3.x.
We also require Puppet version 3.4.0 or greater due to the use of
contains.

metadata.json

@@ -62,10 +62,10 @@
     },
     {
       "name": "puppet",
-      "version_requirement": ">=3.0.0 < 4.0.0"
+      "version_requirement": ">=3.4.0 < 4.0.0"
     }
   ],
   "dependencies": [
-    {"name":"puppetlabs/stdlib","version_requirement":">=2.2.1 <5.0.0"}
+    {"name":"puppetlabs/stdlib","version_requirement":">=3.0.0 <5.0.0"}
   ]
 }