Added support for scala 3.

[rehanone]

Added as WIP as I am not sure what other github workflow changes might be required. This resolves #143.

[regis-leray]

Hello thank you again for your contribution.

Im using sbt github action to generate the ./github/workflows/ci.yml by using sbt githubWorkflowGenerate

So every changes your are doing changes in the file build.sbt, you need to run each time sbt githubWorkflowGenerate.

You cannot modify the file :) you let the plugin do the job

https://github.com/djspiewak/sbt-github-actions

[regis-leray]

try to compile by doing

sbt ++3.0.2 compile

You will get this error

[error] bad option '-Xlint' was ignored
[error] one error found
[error] (Compile / compileIncremental) Compilation failed
[error] Total time: 3 s, completed Oct. 8, 2021, 12:55:53 p.m.

scala3 option changes, you can look inside other repo :) to know which settings are valid

[rehanone]

@regis-leray Thanks, yes I thought I might be making a mistake here. I will make the changes you suggested.

[rehanone]

@regis-leray, Okay it should be good now. Let me know any other items that need to be addressed. Removing the WIP.

[regis-leray]

need a separate rule to have -Xlint activated only for scala2.x but it is not available for scala3
https://docs.scala-lang.org/scala3/guides/migration/options-lookup.html

Example =>
https://github.com/regis-leray/fs2-ftp/blob/master/build.sbt#L75

[rehanone]

Added -Xlint for 2.x.

[regis-leray]

@rehanone thank you