[Bug] cant pass arg value that contains the char '='

[giladw]

🐛 Bug

when passing argument value that contains the char '=' an error is thrown:
ValueError: too many values to unpack (expected 2)

To reproduce

python example.py input_path=s3://rawData/year=2019/month=10/day=29/data_raw_joined.parquet

** Stack trace/error message **

  File "/anaconda3/lib/python3.6/site-packages/hydra/_internal/config_loader.py", line 136, in _apply_defaults_overrides
    key, value = override.split("=")```
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## Expected Behavior
I expect way to pass an argument that contains '=' in some other way

## System information
- 0.10.0
- macOS

[omry]

Hi Gilad,
Thanks for reporting.
This is a pretty simple bug to fix (I think). if you would like to try fixing it I can take a look at a PR.
(Please add tests as well if you do that).

I am traveling so it may take a few weeks before I can fix this).