Fix creating empty directory in zipfile

I'm using a different technique to do that, based on this mailing list answer: https://mail.python.org/pipermail/python-list/2003-June/205859.html

create_plugin.py

@@ -44,6 +44,7 @@ def zipDirectory(path, zip_handle):
     plugin_file_location = plugin_name + ".umplugin"
     with zipfile.ZipFile(plugin_file_location, "w") as plugin_zip:
         # Ensure that the root folder is created correctly. We need to tell zip to not compress the folder!
-        plugin_zip.write(plugin_file_location, arcname = plugin_name, compress_type = zipfile.ZIP_STORED)
+        subdirectory = zipfile.ZipInfo(plugin_name + "/")
+        plugin_zip.writestr(subdirectory, "", compress_type = zipfile.ZIP_STORED) #Writing an empty string creates the directory.
         zipDirectory(full_plugin_path, plugin_zip)
     print("Done!")