[AIRFLOW-5758] Support the custom cursor classes for the PostgreSQL hook

[mingrammer]

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Tests

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[mingrammer]

There is a failed test case.

16) FAIL: test_wait_for_response_running (tests.gcp.hooks.test_kubernetes_engine.TestGKEClusterHook)
----------------------------------------------------------------------
   Traceback (most recent call last):
    /usr/local/lib/python3.6/unittest/mock.py line 1183 in patched
      return func(*args, **keywargs)
    tests/gcp/hooks/test_kubernetes_engine.py line 309 in test_wait_for_response_running
      self.assertEqual(time_mock.call_count, 3)
   AssertionError: 11202 != 3
   -------------------- >> begin captured logging << --------------------
   airflow.gcp.hooks.kubernetes_engine.GKEClusterHook: INFO: Waiting for OPERATION_NAME <Mock name='mock.name' id='140681303781840'>
   --------------------- >> end captured logging << ---------------------

[codecov-io]

Codecov Report

Merging #6432 into master will decrease coverage by 0.6%.
The diff coverage is 84.61%.

@@            Coverage Diff             @@
##           master    #6432      +/-   ##
==========================================
- Coverage   84.26%   83.65%   -0.61%     
==========================================
  Files         627      635       +8     
  Lines       36506    36670     +164     
==========================================
- Hits        30760    30678      -82     
- Misses       5746     5992     +246

Impacted Files	Coverage Δ
airflow/hooks/postgres_hook.py	94.28% <84.61%> (-2.21%)	⬇️
...ow/contrib/example_dags/example_qubole_operator.py	32.5% <0%> (-57.5%)	⬇️
airflow/kubernetes/volume_mount.py	44.44% <0%> (-55.56%)	⬇️
airflow/kubernetes/volume.py	52.94% <0%> (-47.06%)	⬇️
airflow/kubernetes/pod_launcher.py	45.25% <0%> (-46.72%)	⬇️
airflow/kubernetes/kube_client.py	33.33% <0%> (-41.67%)	⬇️
airflow/example_dags/example_python_operator.py	63.33% <0%> (-31.12%)	⬇️
...rflow/contrib/operators/kubernetes_pod_operator.py	70.14% <0%> (-28.36%)	⬇️
airflow/gcp/example_dags/example_dataflow.py	93.33% <0%> (-6.67%)	⬇️
airflow/utils/dag_processing.py	58.15% <0%> (-0.33%)	⬇️
... and 54 more

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[feluelle]

Hey @mingrammer do you also want to add a note to the class docstring about the functionality you added (like the notes about ssl and AWS IAM auth.) ? This way users will have it easier to use it.

[mingrammer]

Sure, I'll do!

[mingrammer]

Done.

[mingrammer]

Some azure-dependant test cases are failing due to azure library changes.

[feluelle]

I see. Let's wait until #6486 is merged and then I rerun the failed ones.

[feluelle]

Thanks @mingrammer :)