[SPARK-15037][SQL][MLLIB] Part2: Use SparkSession instead of SQLContext in Python TestSuites

[techaddict]

What changes were proposed in this pull request?

Use SparkSession instead of SQLContext in Python TestSuites

How was this patch tested?

Existing tests

[SparkQA]

Test build #58330 has finished for PR 13044 at commit d7361d8.

• This patch fails PySpark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #58354 has finished for PR 13044 at commit 7101849.

• This patch fails Python style tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class SparkSessionTestCase(PySparkTestCase):
  • class FeatureTests(SparkSessionTestCase):
  • class CrossValidatorTests(SparkSessionTestCase):
  • class TrainValidationSplitTests(SparkSessionTestCase):
  • class PersistenceTest(SparkSessionTestCase):
  • class LDATest(SparkSessionTestCase):
  • class TrainingSummaryTest(SparkSessionTestCase):
  • class OneVsRestTests(SparkSessionTestCase):
  • class HashingTFTest(SparkSessionTestCase):
  • class ALSTest(SparkSessionTestCase):

[SparkQA]

Test build #58355 has finished for PR 13044 at commit a776c2e.

• This patch fails PySpark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #58358 has finished for PR 13044 at commit 6905326.

• This patch fails Python style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #58359 has finished for PR 13044 at commit 0dbb2a1.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #58366 has finished for PR 13044 at commit d3d4fda.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[techaddict]

cc: @andrewor14 @davies Can you review the PR, Thanks.

[davies]

LGTM,
Merging this into master and 2.0, thanks!