Filter out UNDEFINE_NVRAM for test:///default

The test driver doesn't support UNDEFINE_NVRAM and I couldn't find a way
to probe for the capability. This hacks around it by looking at the
service uri and filters out the flag.

It also adds an explicit test since previously the exception was
swallowed. A new server is created to avoid interference with other
tests.

lib/fog/libvirt/models/compute/server.rb

@@ -97,6 +97,10 @@ def destroy(options={ :destroy_volumes => false, :flags => ::Libvirt::Domain::UN
           if flags.zero?
             service.vm_action(uuid, :undefine)
           else
+            # the test driver doesn't support UNDEFINE_NVRAM
+            if service.uri.driver == 'test'
+              flags ^= ::Libvirt::Domain::UNDEFINE_NVRAM
+            end
             service.vm_action(uuid, :undefine, flags)
           end
           volumes.each { |vol| vol.destroy } if options[:destroy_volumes]

tests/libvirt/models/compute/server_tests.rb

@@ -13,7 +13,7 @@
       %w{ start stop destroy reboot suspend }.each do |action|
         test(action) { server.respond_to? action }
       end
-      %w{ start reboot suspend stop destroy}.each do |action|
+      %w{ start reboot suspend stop }.each do |action|
         test("#{action} returns successfully") {
           begin
             server.send(action.to_sym)
@@ -60,6 +60,11 @@
         end
       end
     end
+
+    test('can destroy') do
+      servers.create(:name => Fog::Mock.random_letters(8)).destroy
+    end
+
     test('be a kind of Fog::Libvirt::Compute::Server') { server.kind_of? Fog::Libvirt::Compute::Server }
     tests("serializes to xml") do
       test("with memory") { server.to_xml.match?(%r{<memory>\d+</memory>}) }