Replace call to "revolver" with call to internal function.
Useful when "revolver" is not defined in PATH.
--- a/revolver
+++ b/revolver
@@ -255,9 +255,9 @@
 ###
 function _revolver_demo() {
   for style in "${(@k)_revolver_spinners[@]}"; do
-    revolver --style $style start $style
+    _revolver --style $style start $style
     sleep 2
-    revolver stop
+    _revolver stop
   done
 }