[ibm|compute] Add request test for list_vlans and fix mock

lib/fog/ibm/requests/compute/list_vlans.rb

@@ -34,15 +34,10 @@ module Fog
         def list_vlans
           response = Excon::Response.new
           response.status = 200
-          response.body = {"addresses"=>
+          response.body = {"vlan"=>
               [{"location"=>"101",
-                "mode"=>0,
-                "offeringId"=>"20001223",
                 "id"=>"75321",
-                "type"=>1,
+                "name"=>"FOG-VLAN1"}]}
-                "ip"=>"170.224.192.210 ",
-                "hostname"=>"170.224.192.210 ",
-                "state"=>2}]},
           response
         end
 

tests/ibm/requests/compute/vlan_tests.rb

@@ -0,0 +1,21 @@
+Shindo.tests('Fog::Compute[:ibm] | location requests', ['ibm']) do
+
+  @vlan_format  = {
+    'id'       => String,
+    'name'     => String,
+    'location' => String,
+  }
+
+  @vlans_format = {
+    'vlan' => [ @vlan_format ]
+  }
+
+  tests('success') do
+
+    tests("#list_vlans").formats(@vlans_format) do
+      Fog::Compute[:ibm].list_vlans.body
+    end
+
+  end
+
+end