sfs/share: Delete share (#120)

diff --git a/openstack/sharedfilesystems/v2/shares/urls.go b/openstack/sharedfilesystems/v2/shares/urls.go
index 4fba746..7cb1c81 100644
--- a/openstack/sharedfilesystems/v2/shares/urls.go
+++ b/openstack/sharedfilesystems/v2/shares/urls.go
@@ -5,3 +5,7 @@
 func createURL(c *gophercloud.ServiceClient) string {
 	return c.ServiceURL("shares")
 }
+
+func deleteURL(c *gophercloud.ServiceClient, id string) string {
+	return c.ServiceURL("shares", id)
+}