Fix omitted snapshot-option

Solves fog#269
Co-authored-by: Ondřej Ezr <ezrik12@gmail.com>

lib/fog/vsphere/requests/compute/vm_take_snapshot.rb

@@ -5,13 +5,17 @@ class Real
         def vm_take_snapshot(options = {})
           raise ArgumentError, 'instance_uuid is a required parameter' unless options.key? 'instance_uuid'
           raise ArgumentError, 'name is a required parameter' unless options.key? 'name'
+          defaults = {
+            description: '',
+            memory: true,
+            quiesce: false
+          }
+          opts = options.clone
+          defaults.each do |k, v|
+            opts[k] = v unless opts.key?(k) || opts.key?(k.to_s)
+          end
           vm = get_vm_ref(options['instance_uuid'])
-          task = vm.CreateSnapshot_Task(
-            name: options['name'],
-            description: options['description'] || '',
-            memory: options['memory'] || true,
-            quiesce: options['quiesce'] || false
-          )
+          task = vm.CreateSnapshot_Task(opts)
 
           task.wait_for_completion