Thanks for much for putting this great library together. I have been testing it for a few days now.

I come to the conclusion that eventLoopGroupProvider should not be a required parameter since it's only used the async-http-client. Should WebPushManager take in an instance of the http client instead? In Hummingbird one can create a single HTTPClientService that gets shared amongst all libraries that needs an instance of the http client.

Please let me know if this is a welcome change as it is also a breaking change. I can a PR out if needed.

I think this deinit can be replaced with the service lifecycle. An example of the service life cycle can be seen here we would simply add WebPushManager as a service graceful shutdown would be handle cleanly

https://github.com/swift-server/swift-service-lifecycle