Avoid non-JS compatible APIs for ScalaTest

[armanbilge]

Not sure if this is too hacky, but this is working on both JVM and JS in circe/circe-fs2#272. The createDefaultScheduler doesn't work on Scala.js.

The alternative is a full cross, or maybe an upstream PR to CE itself.

[armanbilge]

Initial CI failure was unrelated, it was for the utest framework. See a similar failure in c8dac77.

[djspiewak]

This is a little hacky. :-) Why doesn't createDefaultScheduler work on JavaScript? It's present and does the right thing.

[armanbilge]

For some reason I was getting link-time errors?

[armanbilge]

@djspiewak I bumped circe-fs2 to CE 3.2.0 just in case and still get this:

[error] Referring to non-existent method cats.effect.unsafe.IORuntime$.createDefaultScheduler(java.lang.String)scala.Tuple2
[error]   called from cats.effect.testing.scalatest.AsyncIOSpec.$init$()void
[error]   called from constructor io.circe.fs2.Fs2Suite.<init>()void
[error]   called from static constructor io.circe.fs2.Fs2Suite.<stinit>()void
[error]   called from core module analyzer
[error] Referring to non-existent method cats.effect.unsafe.IORuntime$.createDefaultScheduler$default$1()java.lang.String
[error]   called from cats.effect.testing.scalatest.AsyncIOSpec.$init$()void
[error]   called from constructor io.circe.fs2.Fs2Suite.<init>()void
[error]   called from static constructor io.circe.fs2.Fs2Suite.<stinit>()void
[error]   called from core module analyzer
[error] Referring to non-existent method cats.effect.unsafe.IORuntime$.createDefaultScheduler$default$1()java.lang.String
[error]   called from cats.effect.testing.scalatest.AsyncIOSpec.$init$()void
[error]   called from constructor io.circe.fs2.Fs2Suite.<init>()void
[error]   called from static constructor io.circe.fs2.Fs2Suite.<stinit>()void
[error]   called from core module analyzer
[error] Referring to non-existent method cats.effect.unsafe.IORuntime$.createDefaultScheduler(java.lang.String)scala.Tuple2
[error]   called from cats.effect.testing.scalatest.AsyncIOSpec.$init$()void
[error]   called from constructor io.circe.fs2.Fs2Suite.<init>()void
[error]   called from static constructor io.circe.fs2.Fs2Suite.<stinit>()void
[error]   called from core module analyzer

[armanbilge]

Wait, I think I realized the problem ... the build.sbt for cats-effect-testing neglects to use %%% :(