TypeTransformer for Keras

[ryankarlos]

Signed-off-by: Ryan Nazareth [email protected]

TL;DR

Adds a typetransformer to support keras.Model and keras.Sequential as native types

Type

• [ ] Bug Fix
• [x] Feature
• [ ] Plugin

Are all requirements met?

• [x] Code completed
• [x] Smoke tested
• [x] Unit tests added
• [x] Code documentation added
• [ ] Any pending items have an associated Issue

Complete description

• __init__.py file handles case where the user doesn't have keras installed.
• TypeTransformer implemented for the following classes: Sequential: https://keras.io/api/models/sequential/
• added tests in https://github.com/flyteorg/flytekit/tree/master/tests/flytekit/unit/extras/keras

Tracking Issue

https://github.com/flyteorg/flyte/issues/2759

Follow-up issue

N/A