fix: custom_headers not applied

[ffd114]

I've tried adding custom_headers to override URL notifications API as mentioned here but it's not applied when testing using sandbox, after looking at the source, I think it's because the custom_headers is not merged

[Xaxxis]

Hi, @ffd114 that's awesome! At Midtrans we do love community contribution, We will check your PR and review it soon

Thanks for your great contribution

[Xaxxis]

Hi, @ffd114 after checking this, the issue is valid and has been solved by this PR. But we faced an error when try to run the unit test test_is_custom_headers_applied

# Fetch the headers from requests.request arguments
>           headers = mock_request.call_args.kwargs['headers']
E           TypeError: tuple indices must be integers or slices, not str

tests/test_http_client.py:71: TypeError

We will merge this request, improve and make the release. Thank you for your contribution, We are really appropriated

[ffd114]

Hi @Xaxxis glad that it worked, many thanks! Apologize for the unit test