[xenserver|compute] added destroy_vlan request tests

tests/xenserver/requests/compute/destroy_vlan_tests.rb

@@ -0,0 +1,36 @@
+Shindo.tests('Fog::Compute[:xenserver] | destroy_vlan request', ['xenserver']) do
+
+  compute = Fog::Compute[:xenserver]
+
+  tests('success') do
+    test('#destroy_vlan') do
+      @net = compute.networks.create :name => 'test-net'
+
+      # try to use a bonded interface first
+      @pif = compute.pifs.find { |p| p.device == 'bond0' and p.vlan == "-1" }
+      unless @pif
+        @pif = compute.pifs.find { |p| p.device == 'eth0' and p.vlan == "-1" }
+      end
+
+      @ref = compute.create_vlan @pif.reference, 1499, @net.reference
+      compute.destroy_vlan @ref
+      (compute.vlans.reload.find { |v| v.reference == @ref }).nil?
+    end
+  end
+  
+  tests('failure') do
+    test('#destroy_vlan invalid') do
+      raises = false
+      # Try to create a VLAN with a duplicated tag
+      begin
+        compute.destroy_vlan @ref
+      rescue Fog::XenServer::RequestFailed => e
+        raises = true if (e.message =~ /HANDLE_INVALID/)
+      end
+      raises
+    end
+  end
+
+  @net.destroy
+  
+end