title: Specs2 + JUnit + ScalaTest initializationError test class cannot be cast to org.scalatest.Suite
body: <p>I'm following <a href="http://scala-ide.org/docs/current-user-doc/testingframeworks/index.html" rel="nofollow">http://scala-ide.org/docs/current-user-doc/testingframeworks/index.html</a>
  with libs:</p>
  
  <ul>
  <li>"org.specs2" %% "specs2-core" % "2.3.11" % "test"</li>
  <li>"org.scalatest" % "scalatest_2.10" % "2.1.7" % "test"</li>
  <li>JUnit 4.11</li>
  </ul>
  
  <p>test class:</p>
  
  <pre><code>import reactivemongo.bson._
  import org.specs2.mutable._
  import reactivemongo.bson.exceptions.DocumentKeyNotFound
  import reactivemongo.bson.Macros.Annotations.Key
  import org.specs2.runner._
  import org.junit.runner._
  import org.scalatest.junit._
  
  
  @RunWith(classOf[JUnitRunner])
  class MacrosSpec extends Specification  {
  }
  </code></pre>
  
  <p>And I'm getting the initializationError</p>
  
  <pre><code>MacrosSpec
  initializationError(MacrosSpec)
  java.lang.ClassCastException: MacrosSpec cannot be cast to org.scalatest.Suite
  
      at org.scalatest.junit.JUnitRunner.&lt;init&gt;(JUnitRunner.scala:64)
  
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
  
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
  
      at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
  
      at java.lang.reflect.Constructor.newInstance(Unknown Source)
  
      at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:29)
  
      at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:21)
  
      at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
  
      at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
  
      at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
  
      at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:26)
  
      at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.&lt;init&gt;(JUnit4TestReference.java:33)
  
      at org.eclipse.jdt.internal.junit4.runner.JUnit4TestClassReference.&lt;init&gt;(JUnit4TestClassReference.java:25)
  
      at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:48)
  
      at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:38)
  
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452)
  
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
  
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
  
      at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
  </code></pre>
  
  <p>Environment</p>