Add missing openstacklib to dependencies

The vswitch::params class includes the openstacklib::defaults class,
thus puppet-openstacklib should be included in dependencies.

Closes-Bug: #1922026
Change-Id: I3000400e380537f0979c19009dc6c354639c2394
(cherry picked from commit 675cdecba2)

metadata.json

@@ -4,6 +4,10 @@
         {
             "name": "camptocamp/kmod",
             "version_requirement": ">= 0.0.1"
+        },
+        {
+            "name": "openstack/openstacklib",
+            "version_requirement": ">=18.4.0 <19.0.0"
         }
     ],
     "issues_url": "https://bugs.launchpad.net/puppet-vswitch",