Missing dependency (on packaging)

[tdoublep]

It looks like packaging needs to be added to Lale's dependency list.

See following example:

$ conda create -n lale-test python=3.7
$ conda activate lale-test
$ pip install lale
$ python -c "from lale.lib.sklearn import OneHotEncoder"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/tpa/anaconda3/envs/lale-test/lib/python3.7/site-packages/lale/lib/sklearn/__init__.py", line 198, in <module>
    from .one_hot_encoder import OneHotEncoder
  File "/Users/tpa/anaconda3/envs/lale-test/lib/python3.7/site-packages/lale/lib/sklearn/one_hot_encoder.py", line 19, in <module>
    from packaging import version
ModuleNotFoundError: No module named 'packaging'

[shyamsantoki]

This issue is sklearn related. Furthermore, I did not get any errors when I created a conda environment using Python 3.10.

$ conda create -n lale-test python=3.10
$ conda activate lale-test
$ pip install lale
$ python -c "from lale.lib.sklearn import OneHotEncoder"