Added run() function

pd-buddy-gtk.py

         except:
             self.on_header_sink_back_clicked(None)
 
+
 class Application(Gtk.Application):
 
     def __init__(self, *args, **kwargs):
 
         self.window.present()
 
-if __name__ == "__main__":
+
+def run():
     app = Application()
     app.run(sys.argv)
+
+if __name__ == "__main__":
+    run()