old nlp causes error that pip install -e. can't fix.
```
Traceback (most recent call last):
  File "finetune.py", line 15, in <module>
    from lightning_base import BaseTransformer, add_generic_args, generic_train
  File "/home/shleifer/transformers_fork/examples/lightning_base.py", line 10, in <mo
dule>
    from transformers import (
  File "/home/shleifer/transformers_fork/src/transformers/__init__.py", line 23, in <
module>
    from .configuration_albert import ALBERT_PRETRAINED_CONFIG_ARCHIVE_MAP, AlbertConfig
  File "/home/shleifer/transformers_fork/src/transformers/configuration_albert.py", line 18, in <module>
    from .configuration_utils import PretrainedConfig
  File "/home/shleifer/transformers_fork/src/transformers/configuration_utils.py", line 25, in <module>
    from .file_utils import CONFIG_NAME, cached_path, hf_bucket_url, is_remote_url
  File "/home/shleifer/transformers_fork/src/transformers/file_utils.py", line 68, in <module>
    import nlp  # noqa: F401
  File "/home/shleifer/miniconda/envs/torch1.5/lib/python3.8/site-packages/nlp/__init__.py", line 41, in <module>
    raise ImportWarning(
ImportWarning: To use `nlp`, the module `pyarrow>=0.16.0` is required, and the current version of `pyarrow` doesn't match this condition.
If you are running this in a Google Colab, you should probably just restart the runtime to use the right version of `pyarrow`.
```
Fixed with `pip install nlp --upgrade`.
This problem only happens if you do have nlp installed, but an old version.
we could make assertions about` nlp.__version___` to avoid this.<|||||>I face this even now after running pip install on requirements.txt . I just upgrade the version for pyarrow and it works fine then.<|||||>This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.
