GitLab

model_args should only be things that affect output of the model
therefore, stuff like batch size, device, etc shouldn't be in there

Now, if a run gets interrupted halfway, you can easily resume

# Conflicts:
#	lm_eval/models/gpt2.py
#	lm_eval/tasks/squad.py

- Extract evaluator (still needs work to clean up)
- Add tests for evaluator
- Fix all the things that break on the new tests
- Misc cleanup