Log Message:
py-wtforms: Update to 2.3.1.

Version 2.3.1
-------------

Released 2020-04-22

-   All modules in ``wtforms.ext`` show a deprecation warning on import.
    They will be removed in version 3.0.
-   Fixed a bug when :class:`~fields.SelectField` choices is ``None``.
    :issue:`572, 585`
-   Restored ``HTMLString`` and ``escape_html`` as aliases for
    MarkupSafe functions. Their use shows a ``DeprecationWarning``.
    :issue:`581`, :pr:`583`
-   ``Form.validate`` takes an ``extra_validators`` parameter, mapping
    field names to lists of extra validator functions. This matches
    ``BaseForm.validate``. :pr:`584`
-   Update locale catalogs.

Version 2.3.0
-------------

Released 2020-04-21

-   Drop support for Python 2.6, 3.3, and 3.4.
-   :class:`~fields.SelectField` uses ``list()`` to construct a new list
    of choices. :pr:`475`
-   Permitted underscores in ``HostnameValidation``. :pr:`463`
-   :class:`~validators.URL` validator now allows query parameters in
    the URL. :issue:`523`, :pr:`524`
-   Updated ``false_values`` param in ``BooleanField`` docs.
    :issue:`483`, :pr:`485`
-   Fixed broken format string in Arabic translation :pr:`471`
-   Updated French and Japanese translations. :pr:`506, 514`
-   Updated Ukrainian translation. :pr:`433`
-   ``FieldList`` error list keeps entries in order for easier
    identification of which fields had errors. :issue:`257`, :pr:`407`
-   :class:`~validators.Length` gives a more helpful error message when
    ``min`` and ``max`` are the same value. :pr:`266`
-   :class:`~fields.SelectField` no longer coerces ``None`` to
    ``"None"`` allowing use of ``"None"`` as an option. \ 
:issue:`289`,
    :pr:`288`
-   The :class:`~widgets.TextArea` widget prepends a ``\r\n`` newline
    when rendering to account for browsers stripping an initial line for
    display. This does not affect the value. :issue:`238`, :pr:`395`
-   HTML5 :class:`~fields.html5.IntegerField` and
    :class:`~fields.html5.RangeInput` don't render the ``step="1"``
    attribute by default. :pr:`343`
-   ``aria_`` args are rendered the same way as ``data_`` args, by
    converting underscores to hyphens. ``aria_describedby="name-help"``
    becomes ``aria-describedby="name-help"``. :issue:`239`, :pr:`389`
-   Added a ``check_validators`` method to :class:`~fields.Field` which
    checks if the given validators are both callable, and not classes.
    :pr:`298, 410`
-   ``form.errors`` is not cached and will update if an error is
    appended to a field after access. :pr:`568`
-   :class:`~wtforms.validators.NumberRange` correctly handle NaN
    values. :issue:`505`, :pr:`548`
-   :class:`~fields.IntegerField` checks input type when processing
    data. :pr:`451`
-   Added a parameter to :class:`~fields.SelectField` to skip choice
    validation. :issue:`434`, :pr:`493`
-   Choices which name and data are the same do not need to use tuples.
    :pr:`526`
-   Added more documentation on HTML5 fields. :pr:`326, 409`
-   HTML is escaped using MarkupSafe instead of the previous internal
    implementation. :func:`~widgets.core.escape_html` is removed,
    replaced by :func:`markupsafe.escape`.
    :class:`~widgets.core.HTMLString` is removed, replaced by
    :class:`markupsafe.Markup`. :pr:`400`
-   Fixed broken IPv6 validator, validation now uses the ``ipaddress``
    package. :issue:`385`, :pr:`403`
-   :class:`~fields.core.Label` text is escaped before rendering.
    :issue:`315`, :pr:`375`
-   Email validation is now handled by an optional library,
    ``email_validator``. :pr:`429`