Build test_client

[wrenix]

at first: thank you for your build script.

sadly the nice tool test_client is not build on the normal Dockerfile:
https://github.com/nextcloud/notify_push/blob/f791ad1ac93b14d15ffade72fc57a409d2dd56d8/Dockerfile#L9

Do you like to write therefore something?

[miles170]

at first: thank you for your build script.

sadly the nice tool test_client is not build on the normal Dockerfile: https://github.com/nextcloud/notify_push/blob/f791ad1ac93b14d15ffade72fc57a409d2dd56d8/Dockerfile#L9

Do you like to write therefore something?

Including test_client in the image would require patching the original Dockerfile in the repository, and I'm not entirely sure if that would be the best approach. Let me know your thoughts!