FIX docstring deletions
ADD test coverage for _check_stop_list
FIX comment typo
ADD test cases to fill out VectorizerMixin coverage
ADD another VectorizerMixin test
ADD test for get_feature_names
ADD test for tfidf fit with incompatible n_features
ADD test for TfidfVectorizer attribute setters
 MV Mixin tests to CountVectorizer tests
RM CV import
MV _check_stop_list tests to CV get_stop_words
Merge pull request #1660 from rlmv/fe_tests

test cases for feature_extraction.text