Remove unused tfx kubeflow code

[schustmi]

Pre-requisites

Please ensure you have done the following:

• I have read the CONTRIBUTING.md document.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have added tests to cover my changes.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Describe changes

• Cleanup unused kubeflow code

[htahir1]

Did you try testing it on the kubeflow cluster in GCP? :-) If yes, then LGTM!