Log Message:
py-chardet: update to 4.0.0.

This will be the last release of chardet to support Python 2.7.
chardet 5.0 will only support 3.6+

Major Changes

This release is multiple years in the making, and provides some
quality of life improvements to chardet. The primary user-facing
changes are:

    Single-byte charset probers now use nested dictionaries under
    the hood, so they are usually a little faster than before. (See
    #121 for details)

    The CharsetGroupProber class now properly short-circuits when
    one of the probers in the group is considered a definite match.
    This lead to a substantial speedup.

    There is now a chardet.detect_all function that returns a list
    of possible encodings for the input with associated confidences.

    We have dropped support for Python 2.6, 3.4, and 3.5 as they
    are all past end-of-life.

The changes in this release have also laid the groundwork for
retraining the models to make them more accurate, and to support
some more encodings/languages (see #99 for progress). This is our
main focus for chardet 5.0 (beyond dropping Python 2 support).