Replace Connection with gen_statem

[whatyouhide]

Just started on this but all tests pass 🙃 I also tried this branch out in ecto_sql and all tests pass there too. I'll see if I can try it in Postgrex maybe.

[josevalim]

@whatyouhide make sure that you run the integration tests in ecto_sql. :)

[josevalim]

Looks fantastic. But note CI fails. :) And yeah, maybe it is simpler to not update connection indeed, so we keep it "stable".

[whatyouhide]

@josevalim fixed the bug, now mix test.all passes here. Will try the integration tests in ecto_sql.

[josevalim]

@whatyouhide can you check CI? is_exception is not available, you will have to pattern match. :)

[whatyouhide]

Oooph yeah, I stopped checking because it was giving trouble with Erlang/Elixir versions yesterday, and I thought it was still that. Fixed now.

[josevalim]

:green_heart: :blue_heart: :purple_heart: :yellow_heart: :heart: