(#9241) Add vm_clone API request

Without this patch we have no way to clone a new VM
from a template.  This patch adds the vm_clone request
which takes an instance uuid as the source template
to clone from an a name parameter which is the new VM's
name.

The clone operation is handled asynchronously as a vSphere
task object.  The clone request does not return a handle
for this task, which may make it difficult to monitor
the progress of the clone operation from Fog.  A future
enhancement may be to clone and return the task object
itself to monitor progress.

lib/fog/vsphere/compute.rb

@@ -18,6 +18,7 @@ module Fog
       request :vm_power_off
       request :vm_power_on
       request :vm_reboot
+      request :vm_clone
       request :vm_destroy
       request :find_all_by_uuid
       request :find_all_by_instance_uuid

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

@@ -0,0 +1,42 @@
+module Fog
+  module Compute
+    class Vsphere
+      class Real
+
+        def vm_clone(params = {})
+          raise ArgumentError, ":instance_uuid and :name are required" if params.empty?
+          # First, find the Managed Object of the template VM
+          vm = find_template_by_instance_uuid(params[:instance_uuid])
+          # We need to locate the datacenter object to find the
+          # default resource pool.
+          container = vm.parent
+          until container.kind_of? RbVmomi::VIM::Datacenter
+            container = container.parent
+          end
+          dc = container
+          # With the Datacenter Object we can obtain the resource pool
+          resource_pool = dc.hostFolder.children.first.resourcePool
+          # Next, create a Relocation Spec instance
+          relocation_spec = RbVmomi::VIM.VirtualMachineRelocateSpec(:pool => resource_pool,
+                                                                    :transform => 'sparse')
+          # And the clone specification
+          clone_spec = RbVmomi::VIM.VirtualMachineCloneSpec(:location => relocation_spec,
+                                                            :powerOn  => true,
+                                                            :template => false)
+          task = vm.CloneVM_Task(:folder => vm.parent, :name => params[:name], :spec => clone_spec)
+          # REVISIT: We may want to return an identifier for the asyncronous task
+          task.info.state
+        end
+
+      end
+
+      class Mock
+
+        def vm_clone(params = {})
+          "running"
+        end
+
+      end
+    end
+  end
+end