title: Running a jar produce from gradle build
body: <p>I have a simple gradle file from which I build a jar file.<br>
  When I run the jar file however I get and error: 'Exception in thread "main" java.lang.NoClassDefFoundError: scala/Predef$'<br></p>
  
  <p>The build.gradle looks like this:</p>
  
  <pre><code>apply plugin: 'scala'
  apply plugin: 'distribution'
  
  def mainClass = "com.domain.Hello"
  
  distributions {
      custom {}
  }
  
  repositories {
      mavenCentral()
  }
  
  dependencies {
      compile group: 'org.scala-lang', name: 'scala-library', version: '2.11.4'
  }
  
  jar {
      manifest {
          attributes 'Main-Class': mainClass
      }
  }
  
  task run(type: JavaExec, description: "Runs the project") {
      main = mainClass
      classpath sourceSets.main.runtimeClasspath
      classpath configurations.runtime
  }
  </code></pre>