Support coursier (sbt 1.3.0)

[kimxogus]

Since sbt 1.3.0, coursier is enabled by default, and s3 resolver is unrecognized in coursier

resolves += s3resolver
        .value(
          "Ivy Repository",
          s3("repo-bucket-name")
        )
        .withIvyPatterns

generates warning Unrecognized repository REPO_NAME, ignoring it, and for now, useCoursier := false can fix this.

I hope this plugin supports coursier too.