Pandas: FutureWarning

[quantum9Innovation]

covid-notebook/app.py:303: FutureWarning:

The behavior of `series[i:j]` with an integer-dtype index is deprecated.
In a future version, this will be treated as *label-based* indexing, consistent with e.g. `series[i]` lookups.
To retain the old behavior, use `series.iloc[i:j]`. To get the future behavior, use `series.loc[i:j]`.

This warning is due to various updates that will be rolled out in newer versions of Pandas.
This has been first detected after #7, which upgraded pandas to the latest patch release.