Prevent error when creating a state machine with existing name

[alesolano]

Description

Launching a training job raises an error when the name of the state machine is already selected. This is not what we want. If the state machine already exists, we want to update it and run a new execution, without throwing an error.

Requirements

Things you need in order to complete the issue.

• Playing more with stepfunctions CLI. It's not as easy as I thought.

Acceptance Criteria

Criteria that must be met in order to close the issue successfully.

• When launching a new training job with the same state machine name, it does not complain and launches the job.