Skip test if scikit-learn not installed (#1350)

gensim/test/test_sklearn_integration.py

@@ -6,10 +6,14 @@
 import pickle
 
 from scipy import sparse
-from sklearn.pipeline import Pipeline
-from sklearn.feature_extraction.text import CountVectorizer
-from sklearn.datasets import load_files
-from sklearn import linear_model
+try:
+    from sklearn.pipeline import Pipeline
+    from sklearn.feature_extraction.text import CountVectorizer
+    from sklearn.datasets import load_files
+    from sklearn import linear_model
+except:
+    raise unittest.SkipTest("Test requires scikit-learn to be installed, which is not available")
+
 from gensim.sklearn_integration.sklearn_wrapper_gensim_ldamodel import SklearnWrapperLdaModel
 from gensim.sklearn_integration.sklearn_wrapper_gensim_lsimodel import SklearnWrapperLsiModel
 from gensim.corpora import Dictionary