add tests after rebasing

Author: solegalli

boruta/test/test_boruta.py

@@ -64,4 +64,4 @@ def test_dataframe_is_returned(Xy):
     rfc = RandomForestClassifier()
     bt = BorutaPy(rfc)
     bt.fit(X_df, y_df)
-    assert isinstance(bt.transform(X_df, return_df=True), pd.DataFrame)
+    assert isinstance(bt.transform(X_df, return_df=True), pd.DataFrame)