Set some variables that are not used later to None in text.py, in order to save file size during pickle object serialization later in CloudML.
Set some variables that are not used later to None in text.py, in order to save file size during pickle object serialization later in CloudML.

ashhher3/scikit-learn,ashhher3/scikit-learn,ashhher3/scikit-learn,ashhher3/scikit-learn