Finishing off add user roles :zap:
diff --git a/openstack/identity/v2/extensions/admin/roles/urls.go b/openstack/identity/v2/extensions/admin/roles/urls.go
index 2ab2b5d..9400782 100644
--- a/openstack/identity/v2/extensions/admin/roles/urls.go
+++ b/openstack/identity/v2/extensions/admin/roles/urls.go
@@ -2,15 +2,16 @@
 
 import "github.com/rackspace/gophercloud"
 
-const (
-	extPath  = "OS-KSADMN"
-	rolePath = "roles"
-)
+const extPath = "OS-KSADMN/roles"
 
 func resourceURL(c *gophercloud.ServiceClient, id string) string {
-	return c.ServiceURL(extPath, rolePath, id)
+	return c.ServiceURL(extPath, id)
 }
 
 func rootURL(c *gophercloud.ServiceClient) string {
-	return c.ServiceURL(extPath, rolePath)
+	return c.ServiceURL(extPath)
+}
+
+func userRoleURL(c *gophercloud.ServiceClient, tenantID, userID, roleID string) string {
+	return c.ServiceURL("tenants", tenantID, "users", userID, extPath, roleID)
 }