build: use poetry for reproducible virtual environments

[VassilisVassiliadis]

Description of the change

• Use poetry:
  1. to build reproducible virtual environments
  2. during CI/CD testing
  3. to build the container image
• Update test_launch_script.py to handle exceptions that accelerate.commands.launch.launch_command(args) raises when the accelerate option num_processes is greater than 1
• Update tests in test_launch_script.py to try and use a free port. This is useful if you have a default accelerate_config.yml file (e.g. under ~/.cache/transformers) with a num_processes > 1 field.
• Updated tests that set the training argument --eval_strategy epoch to fallback to --evaluation_strategy for backwards compatibility with older version of transformers (e.g. 4.39.3).
  • due to fms_acceleration having a constraint to transformers<4.40.0 transformers gets set to 4.39.3 when you use poetry to install fms-hf-tuning (even if you do not add the cli arg --with fms-accel).
  • This PR introduces a method get_train_args() in test_sft_trainer.py for building the configs.TrainingArguments object

Related issue number

Contributes to #60

How to verify the PR

Use poetry install to install fms-hf-tuning from source. You will end up installing the python dependencies listed in poetry.lock

Was the PR tested

• [ ] I have added >=1 unit test(s) for every new method I have added.
• [x] I have ensured all unit tests pass

[VassilisVassiliadis]

I updated the description of the issue with a couple more changes that I had to do for the tests to pass.