BUG: UnknownTimezoneWarning from df.to_datetime()
I have `test.csv`:
```
datetime
Oct 19, 2020 06:58:20 PM EDT
Oct 19, 2020 04:45:33 PM EDT
```

and `test.py`:
```
import pandas as pd
from datetime import datetime

input_file_path = 'test.csv'

df = pd.read_csv(input_file_path, delimiter=';')

print(df)

df['datetime'] = pd.to_datetime(df['datetime'])

print(df)
```

Running `python test.py` results in:
```
                       datetime
0  Oct 19, 2020 06:58:20 PM EDT
1  Oct 19, 2020 04:45:33 PM EDT
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/dateutil/parser/_parser.py:1218: UnknownTimezoneWarning: tzname EDT identified but not understood.  Pass `tzinfos` argument in order to correctly return a timezone-aware datetime.  In a future version, this will raise an exception.
  category=UnknownTimezoneWarning)
             datetime
0 2020-10-19 18:58:20
1 2020-10-19 16:45:33
```

The `UnknownTimezoneWarning` from `dateutil` is what I am concerned about. I don't believe there is currently a way to pass an argument to `panda`'s `to_datetime()` to avoid this. Am I missing something or does this need to be addressed?

Running with `pandas` v1.2.0, `python` v3.7.3.