Migrate e2e testing to integration_test

[ened]

You can run the test in the example folder, using:

fvm flutter drive --driver=test_driver/integration_test.dart --target=integration_test/visitor_info_test.dart

We can not bump to Flutter2.x yet as the integration_test and pigeon packages are incompatible with each other. The PRs are on deck, for example here: flutter/packages#315

Looks like migration will be possible with Flutter 2.1+

[ened]

@emostar for your review

[ryanheise]

Would be nice to have this merged because the null safety migration (#35 ) can't happen without this.

Regarding pigeon, I've personally stayed away from it as I find it a bit too experimental, incomplete and rough around the edges. A quick and dirty approach to null safety (not worth merging but addressing any immediate needs) would be to migrate the generated pigeon code, so I may try to do that based on this fork.

[ened]

@ryanheise things have moved on - pigeon may be a lot more stable now. @emostar do you still have interest in maintaining this plugin?

[ryanheise]

My experience with using pigeon on a project was that it was nice, until I ran into a limitation and realised there was no way around it (on that occasion it was that pigeon didn't then support asynchronous methods.) It's slowly gaining more features but there's still just too much missing for now (e.g. flutter/flutter#66711 and flutter/flutter#66710). I'll probably give it another go in a year.

[emostar]

@ryanheise things have moved on - pigeon may be a lot more stable now. @emostar do you still have interest in maintaining this plugin?

@ened Yes, I'm actually using this plugin in production apps. I may not always be very responsive here, as I have many obligations. If anyone is willing to help me out, I can add them to this repository and flutter pub so it's not dependent on me for every change and release.

[ened]

Yes why not. @emostar Let's do it.

[emostar]

@ened I'll need your pub.dev email address to add you to the project.

[ened]

@ened I'll need your pub.dev email address to add you to the project.

<firstname>.<lastname>@gmail.com thx