Fixed some cut and paste fail with the currently unwritten Mocks

lib/fog/compute/requests/voxel/devices_list.rb

@@ -34,7 +34,7 @@ module Fog
       end
 
       class Mock
-        def images_list
+        def devices_list
           Fog::Mock.not_implemented
         end
       end

lib/fog/compute/requests/voxel/voxcloud_create.rb

@@ -17,7 +17,7 @@ module Fog
       end
 
       class Mock
-        def images_list
+        def voxcloud_create( options )
           Fog::Mock.not_implemented
         end
       end

lib/fog/compute/requests/voxel/voxcloud_status.rb

@@ -25,7 +25,7 @@ module Fog
       end
 
       class Mock
-        def images_list
+        def voxcloud_status( device_id = nil )
           Fog::Mock.not_implemented
         end
       end