title: snakeyaml and spark results in an inability to construct objects
body: <p>The following code executes fine in a scala shell given snakeyaml version 1.17</p>
  
  <pre><code>import org.yaml.snakeyaml.Yaml
  import org.yaml.snakeyaml.constructor.Constructor
  import scala.collection.mutable.ListBuffer
  import scala.beans.BeanProperty
  
  class EmailAccount {
    @scala.beans.BeanProperty var accountName: String = null
  
    override def toString: String = {
      return s"acct ($accountName)"
    }
  }
  
  val text = """accountName: Ymail Account"""
  
  val yaml = new Yaml(new Constructor(classOf[EmailAccount]))
  val e = yaml.load(text).asInstanceOf[EmailAccount]
  println(e)
  </code></pre>
  
  <p>However when running in spark (2.0.0 in this case) the resulting error is:</p>
  
  <pre><code>org.yaml.snakeyaml.constructor.ConstructorException: Can't construct a java object for tag:yaml.org,2002:EmailAccount; exception=java.lang.NoSuchMethodException: EmailAccount.&lt;init&gt;()
   in 'string', line 1, column 1:
      accountName: Ymail Account
      ^
  
    at org.yaml.snakeyaml.constructor.Constructor$ConstructYamlObject.construct(Constructor.java:350)
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182)
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument(BaseConstructor.java:141)
    at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:127)
    at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:450)
    at org.yaml.snakeyaml.Yaml.load(Yaml.java:369)
    ... 48 elided
  Caused by: org.yaml.snakeyaml.error.YAMLException: java.lang.NoSuchMethodException: EmailAccount.&lt;init&gt;()
    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.createEmptyJavaBean(Constructor.java:220)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.construct(Constructor.java:190)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructYamlObject.construct(Constructor.java:346)
    ... 53 more
  Caused by: java.lang.NoSuchMethodException: EmailAccount.&lt;init&gt;()
    at java.lang.Class.getConstructor0(Class.java:2810)
    at java.lang.Class.getDeclaredConstructor(Class.java:2053)
    at org.yaml.snakeyaml.constructor.Constructor$ConstructMapping.createEmptyJavaBean(Constructor.java:216)
    ... 55 more
  </code></pre>
  
  <p>I launched the scala shell with </p>
  
  <pre><code>scala -classpath "/home/placey/snakeyaml-1.17.jar"
  </code></pre>
  
  <p>I launched the spark shell with</p>
  
  <pre><code>/home/placey/Downloads/spark-2.0.0-bin-hadoop2.7/bin/spark-shell --master local --jars /home/placey/snakeyaml-1.17.jar
  </code></pre>