[ovirt] Add support for reading the oVirt api version.

lib/fog/ovirt/compute.rb

@@ -42,6 +42,7 @@ module Fog
       request :list_template_volumes
       request :add_volume
       request :destroy_volume
+      request :get_api_version
 
       module Shared
         # converts an OVIRT object into an hash for fog to consume.

lib/fog/ovirt/requests/compute/get_api_version.rb

@@ -0,0 +1,16 @@
+module Fog
+  module Compute
+    class Ovirt
+      class Real
+        def api_version
+          client.api_version
+        end
+      end
+      class Mock
+        def api_version
+          "3.1"
+        end
+      end
+    end
+  end
+end