Remove PE requirement from metadata.json

The PE requirement in metadata.json is not
supported anymore and puppet-lint will throw:

The 'pe' requirement is no longer supported by the Forge.

Change-Id: Ia6e420d3f3457407da7bcf4d52214dbf04a96c32

metadata.json

@@ -79,10 +79,6 @@
     ],
     "project_page": "https://launchpad.net/puppet-nova",
     "requirements": [
-        {
-            "name": "pe",
-            "version_requirement": "4.x"
-        },
         {
             "name": "puppet",
             "version_requirement": "4.x"
@@ -91,4 +87,4 @@
     "source": "git://github.com/openstack/puppet-nova.git",
     "summary": "Puppet module for OpenStack Nova",
     "version": "13.3.0"
-}
+}