Support for HashingTFModel

[avisheknag17]

Hi,

I didn't find support for HashingTF. I need to do TF-IDF transformation for text
I am getting this exception:

Traceback (most recent call last):
File "/opt/spark-2.2.1-master/bin/enclosures_pyspark_model.py", line 125, in
build_and_train_model()
File "/opt/spark-2.2.1-master/bin/enclosures_pyspark_model.py", line 121, in build_and_train_model
pmmlBuilder.buildFile("enclosures_pyspark_model.pmml")
File "/Users/avnag/Library/Python/2.7/lib/python/site-packages/pyspark2pmml/init.py", line 27, in buildFile
javaFile = self.javaPmmlBuilder.buildFile(javaFile)
File "/opt/spark-2.2.1-master/python/lib/py4j-0.10.4-src.zip/py4j/java_gateway.py", line 1133, in call
File "/opt/spark-2.2.1-master/python/lib/pyspark.zip/pyspark/sql/utils.py", line 79, in deco
pyspark.sql.utils.IllegalArgumentException: u'Transformer class org.apache.spark.ml.feature.HashingTF is not supported'

[vruusmann]

Duplicate of #20