Update attrs to 20.3.0

[pyup-bot]

This PR updates attrs from 20.2.0 to 20.3.0.

Changelog

20.3.0

-------------------

Backward-incompatible Changes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

- ``attr.define()``, ``attr.frozen()``, ``attr.mutable()``, and ``attr.field()`` remain **provisional**.

This release does **not** change change anything about them and they are already used widely in production though.

If you wish to use them together with mypy, you can simply drop `this plugin <https://gist.github.com/hynek/1e3844d0c99e479e716169034b5fa963file-attrs_ng_plugin-py>`_ into your project.

Feel free to provide feedback to them in the linked issue 668.

We will release the ``attrs`` namespace once we have the feeling that the APIs have properly settled.
`668 <https://github.com/python-attrs/attrs/issues/668>`_


Changes
^^^^^^^

- ``attr.s()`` now has a *field_transformer* hook that is called for all ``Attribute``\ s and returns a (modified or updated) list of ``Attribute`` instances.
``attr.asdict()`` has a *value_serializer* hook that can change the way values are converted.
Both hooks are meant to help with data (de-)serialization workflows.
`653 <https://github.com/python-attrs/attrs/issues/653>`_
- ``kw_only=True`` now works on Python 2.
`700 <https://github.com/python-attrs/attrs/issues/700>`_
- ``raise from`` now works on frozen classes on PyPy.
`703 <https://github.com/python-attrs/attrs/issues/703>`_,
`712 <https://github.com/python-attrs/attrs/issues/712>`_
- ``attr.asdict()`` and ``attr.astuple()`` now treat ``frozenset``\ s like ``set``\ s with regards to the *retain_collection_types* argument.
`704 <https://github.com/python-attrs/attrs/issues/704>`_
- The type stubs for ``attr.s()`` and ``attr.make_class()`` are not missing the *collect_by_mro* argument anymore.
`711 <https://github.com/python-attrs/attrs/issues/711>`_


----

Links

• PyPI: https://pypi.org/project/attrs
• Changelog: https://pyup.io/changelogs/attrs/
• Homepage: https://www.attrs.org/

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@e9e3ed0). Click here to learn what that means.
The diff coverage is 97.39%.

@@            Coverage Diff            @@
##             master    #1407   +/-   ##
=========================================
  Coverage          ?   83.99%           
=========================================
  Files             ?       48           
  Lines             ?      681           
  Branches          ?        0           
=========================================
  Hits              ?      572           
  Misses            ?      109           
  Partials          ?        0           

Impacted Files	Coverage Δ
pypro/modulos/apps.py	0.00% <0.00%> (ø)
pypro/turmas/apps.py	0.00% <0.00%> (ø)
pypro/urls.py	71.42% <ø> (ø)
pypro/modulos/migrations/0003_populando_slug.py	80.00% <80.00%> (ø)
pypro/settings.py	65.21% <90.00%> (ø)
pypro/aperitivos/models.py	90.90% <90.90%> (ø)
pypro/modulos/models.py	92.30% <92.30%> (ø)
pypro/aperitivos/admin.py	100.00% <100.00%> (ø)
pypro/aperitivos/migrations/0001_initial.py	100.00% <100.00%> (ø)
...o/aperitivos/migrations/0002_auto_20190910_0940.py	100.00% <100.00%> (ø)
... and 34 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e9e3ed0...0366604. Read the comment docs.

[pyup-bot]

Closing this in favor of #1735