title: Initializing Apache Beam Test Pipeline in Scala fails
body: <p>When I try to run a test pipeline it raise an error </p>
  
  <p>here is the source code to create the test pipeline:</p>
  
  <pre><code>val p: TestPipeline = TestPipeline.create()
  </code></pre>
  
  <p>and here is the error : </p>
  
  <blockquote>
    <p>java.lang.IllegalStateException: Is your TestPipeline declaration missing a @Rule annotation? Usage: @Rule public final transient TestPipeline pipeline = TestPipeline.create();</p>
  </blockquote>