Add upper version bound on scikit-learn, tighten GridSearchCV doctest

Author: smurching

python/requirements.txt

@@ -1,2 +1,2 @@
 # This file should list any python package dependencies.
-scikit-learn>=0.18.1
+scikit-learn>=0.18.1, <=0.19

python/setup.py

@@ -19,7 +19,7 @@
     "Programming Language :: Python",
     "Topic :: Scientific/Engineering",
 ]
-INSTALL_REQUIRES = ["scikit-learn >= 0.18.1"]
+INSTALL_REQUIRES = ["scikit-learn >=0.18.1, <= 0.19"]
 
 # Project root
 ROOT = os.path.abspath(os.getcwd() + "/")

python/spark_sklearn/grid_search.py

@@ -127,7 +127,7 @@ class GridSearchCV(BaseSearchCV):
                          kernel='rbf', max_iter=-1, probability=False,
                          random_state=None, shrinking=True, tol=...,
                          verbose=False),
-           fit_params=..., iid=..., n_jobs=1,
+           fit_params={}, iid=..., n_jobs=1,
            param_grid=..., pre_dispatch=..., refit=...,
            scoring=..., verbose=...)
     >>> sorted(clf.cv_results_.keys())