Fix sdk test issue that's caused by kubenertes Client bug.

[jinchihe]

The PR is going to debug and fix the SDK CI tests problem below.

           obj_dict = {obj.attribute_map[attr]: getattr(obj, attr)
>                       for attr, _ in six.iteritems(obj.openapi_types)
                       if getattr(obj, attr) is not None}
E           AttributeError: 'V1TFJob' object has no attribute 'openapi_types'
/usr/local/lib/python3.5/dist-packages/kubernetes/client/api_client.py:230: AttributeError

This is caused by kubernetes Client bug: kubernetes-client/python#1112

---

This change is 

[jinchihe]

That's new kubernetes Client bug, already work around by using old version

PASSED                                                                   [ 12%]
sdk/python/test/test_v1_job_condition.py::TestV1JobCondition::testV1JobCondition PASSED [ 25%]
sdk/python/test/test_v1_job_status.py::TestV1JobStatus::testV1JobStatus PASSED [ 37%]
sdk/python/test/test_v1_replica_spec.py::TestV1ReplicaSpec::testV1ReplicaSpec PASSED [ 50%]
sdk/python/test/test_v1_replica_status.py::TestV1ReplicaStatus::testV1ReplicaStatus PASSED [ 62%]
sdk/python/test/test_v1_tf_job.py::TestV1TFJob::testV1TFJob PASSED       [ 75%]
sdk/python/test/test_v1_tf_job_list.py::TestV1TFJobList::testV1TFJobList PASSED [ 87%]
sdk/python/test/test_v1_tf_job_spec.py::TestV1TFJobSpec::testV1TFJobSpec PASSED [100%]
generated xml file: /mnt/test-data-volume/kubeflow-tf-operator-presubmit-v1-1143-f04c451-1427-56e9/output/artifacts/junit_sdk-test.xml
========================== 8 passed in 153.92 seconds ==========================

[coveralls]

Coverage remained the same at 96.512% when pulling 06dffdd on jinchihe:fix_sdk_ci_issue into 07cb99e on kubeflow:master.

[gaocegege]

/lgtm
/approve
Thanks

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gaocegege

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• sdk/python/OWNERS [gaocegege]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[631068264]

When to release 1.0.4 version ?