change CreateOpts from structure to map to avoid default null values
diff --git a/openstack/blockstorage/v1/client.go b/openstack/blockstorage/v1/client.go
index 4547d0b..dfce924 100644
--- a/openstack/blockstorage/v1/client.go
+++ b/openstack/blockstorage/v1/client.go
@@ -22,10 +22,14 @@
 	}
 }
 
-func (c *Client) GetVolumeURL() string {
+func (c *Client) GetVolumesURL() string {
 	return fmt.Sprintf("%s/volumes", c.endpoint)
 }
 
+func (c *Client) GetVolumeURL(id string) string {
+	return fmt.Sprintf("%s/volumes/%s", c.endpoint, id)
+}
+
 func (c *Client) GetHeaders() (map[string]string, error) {
 	t, err := c.getAuthToken()
 	if err != nil {