Add support for scala 2.13.0-M3

[alexarchambault]

No description provided.

[SethTisue]

2.13.0-M4 is out now.

the Scala 2.13 community build shows that the new collections landing means some changes are needed here. I'm seeing compile errors such as:

[utest] [error]  found   : scala.collection.mutable.Buffer[utest.framework.Tree[String]]
[utest] [error]  required: Seq[utest.framework.Tree[String]]
[utest] [error]     for (grouping <- ordered) yield {

because default Seq is now immutable, and

[utest] [error] /Users/tisue/community.213/target-0.9.12/project-builds/utest-0ca1a9d492311923bb1834281006436668721bd4/utest/shared/src/main/scala/utest/TestRunner.scala:206: value appendAll is not a member of scala.collection.mutable.Buffer[Seq[String]]
[utest] [error]       case Left(l) => left.appendAll(l)
[utest] [error]                            ^

because appendAll is called something else now.

[SethTisue]

is there a volunteer who could work on this...?

[alexarchambault]

If no one peeks that in the mean time, me… around September / October!

[dwijnand]

#163 makes the code changes, but not the build changes.

[SethTisue]

is there some we can move forward on this..? anyone available to tackle it?

[SethTisue]

Scala 2.13.0-M5 is now out

[japgolly]

I'm not putting my hand up to make these changes but if someone else is able to contribute a PR, I can put my hand up to do the review and merge. I completely forgot that I'm a maintainer of utest 😆