Remove unused imports and format imports outside of `lm_eval` module

main.py

@@ -2,8 +2,6 @@ import argparse
 import json
 import numpy as np
 import random
-import itertools
-import collections
 import logging
 
 from lm_eval import models, tasks, evaluator, base

scripts/cost_estimate.py

-import argparse
-import json
-import numpy as np
 import random
-import itertools
-import collections
-import logging
-
-from lm_eval import models, tasks, evaluator, base
-import random
-from lm_eval.base import LM
 import transformers
+from lm_eval import tasks, evaluator
+from lm_eval.base import LM
 
 
 class DryrunLM(LM):

scripts/fewshot_description_experiment.py

-import argparse
 import json
 import numpy as np
 import random
-import itertools
-import collections
 import logging
-
 from lm_eval import models, tasks, evaluator, base
 
 logging.getLogger("openai").setLevel(logging.WARNING)

scripts/write_out.py

@@ -2,7 +2,6 @@ import argparse
 import numpy as np
 import os
 import random
-
 from lm_eval import tasks
 from lm_eval.utils import join_iters
 

tests/test_models.py

 import lm_eval.models as models
-import lm_eval.base as base
+
 
 def test_gpt2():
     gpt2 = models.get_model('gpt2').create_from_arg_string("device=cpu")

tests/test_tasks.py

 import lm_eval.tasks as tasks
 import lm_eval.base as base
-from itertools import islice
 import pytest
+from itertools import islice
 
 
 @pytest.mark.parametrize("taskname,Task", tasks.TASK_REGISTRY.items())