Marshmallow

+++++++++++++++++++

Bug fixes:

- Prevent memory leak when dynamically creating classes with ``type()``
(:issue:`732`). Thanks :user:`asmodehn` for writing the tests to
reproduce this issue.

+++++++++++++++++++

Bug fixes:

- Prevent warning about importing from ``collections`` on Python 3.7
(:issue:`1027`). Thanks :user:`nkonin` for reporting and
:user:`jmargeta` for the PR.

+++++++++++++++++++

Bug fixes:

- Remove spurious warning about implicit collection handling
(:issue:`998`). Thanks :user:`lalvarezguillen` for reporting.

+++++++++++++++++++

Bug fixes:

- Allow username without password in basic auth part of the url in
``fields.Url`` (:pr:`982`). Thanks user:`alefnula` for the PR.

Other changes:

- Drop support for Python 3.3 (:pr:`987`).

+++++++++++++++++++

Bug fixes:

- Prevent ``TypeError`` when a non-collection is passed to a ``Schema`` with ``many=True``.
Instead, raise ``ValidationError`` with ``{'_schema': ['Invalid input type.']}`` (:issue:`906`).
- Fix ``root`` attribute for nested container fields on list
on inheriting schemas (:issue:`956`). Thanks :user:`bmcbu`
for reporting.

These fixes were backported from 3.0.0b15 and 3.0.0b16.

+++++++++++++++++++

Bug fixes:

- Handle empty SQLAlchemy lazy lists gracefully when dumping (:issue:`948`).
Thanks :user:`vke-code` for the catch and :user:`YuriHeupa` for the patch.