[SPARK-10615] [PYSPARK] change assertEquals to assertEqual

As ```assertEquals``` is deprecated, so we need to change ```assertEquals``` to ```assertEqual``` for existing python unit tests.

Author: Yanbo Liang <[email protected]>

Closes #8814 from yanboliang/spark-10615.

Author: yanboliang

python/pyspark/ml/tests.py

@@ -182,7 +182,7 @@ def test_params(self):
         self.assertEqual(testParams.getMaxIter(), 10)
         testParams.setMaxIter(100)
         self.assertTrue(testParams.isSet(maxIter))
-        self.assertEquals(testParams.getMaxIter(), 100)
+        self.assertEqual(testParams.getMaxIter(), 100)
 
         self.assertTrue(testParams.hasParam(inputCol))
         self.assertFalse(testParams.hasDefault(inputCol))
@@ -195,7 +195,7 @@ def test_params(self):
         testParams._setDefault(seed=41)
         testParams.setSeed(43)
 
-        self.assertEquals(
+        self.assertEqual(
             testParams.explainParams(),
             "\n".join(["inputCol: input column name (undefined)",
                        "maxIter: max number of iterations (>= 0) (default: 10, current: 100)",
@@ -264,23 +264,23 @@ def test_ngram(self):
         self.assertEqual(ngram0.getInputCol(), "input")
         self.assertEqual(ngram0.getOutputCol(), "output")
         transformedDF = ngram0.transform(dataset)
-        self.assertEquals(transformedDF.head().output, ["a b c d", "b c d e"])
+        self.assertEqual(transformedDF.head().output, ["a b c d", "b c d e"])
 
     def test_stopwordsremover(self):
         sqlContext = SQLContext(self.sc)
         dataset = sqlContext.createDataFrame([Row(input=["a", "panda"])])
         stopWordRemover = StopWordsRemover(inputCol="input", outputCol="output")
         # Default
-        self.assertEquals(stopWordRemover.getInputCol(), "input")
+        self.assertEqual(stopWordRemover.getInputCol(), "input")
         transformedDF = stopWordRemover.transform(dataset)
-        self.assertEquals(transformedDF.head().output, ["panda"])
+        self.assertEqual(transformedDF.head().output, ["panda"])
         # Custom
         stopwords = ["panda"]
         stopWordRemover.setStopWords(stopwords)
-        self.assertEquals(stopWordRemover.getInputCol(), "input")
-        self.assertEquals(stopWordRemover.getStopWords(), stopwords)
+        self.assertEqual(stopWordRemover.getInputCol(), "input")
+        self.assertEqual(stopWordRemover.getStopWords(), stopwords)
         transformedDF = stopWordRemover.transform(dataset)
-        self.assertEquals(transformedDF.head().output, ["a"])
+        self.assertEqual(transformedDF.head().output, ["a"])
 
 
 class HasInducedError(Params):