title: ImportError: No module named sparkdl.image.imageIO
body: <p>i'm doing image classification using spark.
  i have already imported sparkdl jar(added path of jar in the conf/spark.default)</p>
  
  <pre><code>ImportError: No module named sparkdl.image.imageIO
      at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRDD.scala:193)
      at org.apache.spark.api.python.PythonRunner$$anon$1.&lt;init&gt;(PythonRDD.scala:234)
      at org.apache.spark.api.python.PythonRunner.compute(PythonRDD.scala:152)
      at org.apache.spark.sql.execution.python.BatchEvalPythonExec$$anonfun$doExecute$1.apply(BatchEvalPythonExec.scala:144)
      at org.apache.spark.sql.execution.python.BatchEvalPythonExec$$anonfun$doExecute$1.apply(BatchEvalPythonExec.scala:87)
      at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1$$anonfun$apply$23.apply(RDD.scala:797)
      at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1$$anonfun$apply$23.apply(RDD.scala:797)
      at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
      at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:323)
      at org.apache.spark.rdd.RDD.iterator(RDD.scala:287)
      at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
      at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:323)
      at org.apache.spark.rdd.RDD.iterator(RDD.scala:287)
      at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
      at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:323)
      at org.apache.spark.rdd.RDD.iterator(RDD.scala:287)
      at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87)
      at org.apache.spark.scheduler.Task.run(Task.scala:99)
      at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:322)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
      at java.lang.Thread.run(Thread.java:748)
  
  Caused by: org.apache.spark.api.python.PythonException: Traceback (most recent call last):
    File "/home/ubuntu/install/spark-2.1.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/worker.py", line 161, in main
      func, profiler, deserializer, serializer = read_udfs(pickleSer, infile)
    File "/home/ubuntu/install/spark-2.1.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/worker.py", line 91, in read_udfs
      _, udf = read_single_udf(pickleSer, infile)
    File "/home/ubuntu/install/spark-2.1.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/worker.py", line 78, in read_single_udf
      f, return_type = read_command(pickleSer, infile)
    File "/home/ubuntu/install/spark-2.1.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/worker.py", line 54, in read_command
      command = serializer._read_with_length(file)
    File "/home/ubuntu/install/spark-2.1.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/serializers.py", line 169, in _read_with_length
      return self.loads(obj)
    File "/home/ubuntu/install/spark-2.1.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/serializers.py", line 454, in loads
      return pickle.loads(obj)
  ImportError: No module named sparkdl.image.imageIO
      at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRDD.scala:193)
  </code></pre>
  
  <p><code>from sparkd import readImages</code>
  when i read image it work good ,
  but when create model and fit the image DataFrame that time it gives 
  No module named sparkdl.image.imageIO</p>