Adding DeleteResult for rackspace.blockstorage.v1.volumes.Delete
diff --git a/rackspace/blockstorage/v1/volumes/results.go b/rackspace/blockstorage/v1/volumes/results.go
index c7c2cc4..9435dca 100644
--- a/rackspace/blockstorage/v1/volumes/results.go
+++ b/rackspace/blockstorage/v1/volumes/results.go
@@ -25,6 +25,11 @@
 	os.UpdateResult
 }
 
+// DeleteResult represents the result of a delete operation
+type DeleteResult struct {
+	os.DeleteResult
+}
+
 func commonExtract(resp interface{}, err error) (*Volume, error) {
 	if err != nil {
 		return nil, err