Results 4 issues of Alex

On Scala 2.13 with `-Xsource:2.14` compiler option, newtype macro gives the following warning ``` Auto-application to `()` is deprecated. Supply the empty argument list `()` explicitly to invoke method hashCode,...

Awaiting for Spinoco/protocol#62 I tried it locally and all the tests passed

Client lib could not detect `DBNotFoundError` in all cases, because of different error messages.

scodec is now published for 2.13. so this project could move as well. I could offer a help with it, if you are interested