Add “ends here” footer

It’s useless, but required by package-lint.

pip-frame.el

@@ -4,6 +4,7 @@
 
 ;; Author: Milan Zamazal <pdm@zamazal.org>
 ;; Package-Version: 1
+;; Package-Requires: ((emacs "25.1"))
 ;; Keywords: frames
 ;; URL: https://git.zamazal.org/pdm/pip-frame
 
@@ -225,3 +226,5 @@ Any other key stops this command and executes its own command."
   (set-transient-map pip-frame-move-map t))
 
 (provide 'pip-frame)
+
+;;; pip-frame.el ends here