Make Scala.js happy

Author: smarter

project/Build.scala

@@ -866,6 +866,9 @@ object Build {
     settings(
       scalacOptions --= Seq("-Xfatal-warnings", "-deprecation"),
 
+      // Required to run Scala.js tests.
+      fork in Test := false,
+
       sourceDirectory in fetchScalaJSSource := target.value / s"scala-js-src-$scalaJSVersion",
 
       fetchScalaJSSource := {