merge master to temp/docs for updating the documentation (microsoft#134)

* merge master to documentation branch

* fixed the ModuleNotFoundError for WordEmbedding_df.py

src/python/nimbusml/examples/examples_from_dataframe/WordEmbedding_df.py

@@ -3,7 +3,7 @@
 import pandas
 from nimbusml import Pipeline
 from nimbusml.feature_extraction.text import WordEmbedding
-from nimbusml.feature_extraction.text.ngramfeaturizer import NGramFeaturizer
+from nimbusml.feature_extraction.text import NGramFeaturizer
 from nimbusml.feature_extraction.text.extractor import Ngram
 
 # create the data