Expose reboot server support.
diff --git a/interfaces.go b/interfaces.go
index de1f7c8..e05bdc4 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -35,6 +35,7 @@
 	ResizeServer(id, newName, newFlavor, newDiskConfig string) error
 	RevertResize(id string) error
 	ConfirmResize(id string) error
+	RebootServer(id string, hard bool) error
 
   // Images