Update sphinx-autoapi to 1.5.0

[pyup-bot]

This PR updates sphinx-autoapi from 1.4.0 to 1.5.0.

Changelog

1.5.0

---------

This will be the last minor version to support Python 2 and Sphinx 1.x/2.x.

Features
^^^^^^^^
* `222 <https://github.com/readthedocs/sphinx-autoapi/issues/222>`:
Declare the extension as parallel unsafe.
* `217 <https://github.com/readthedocs/sphinx-autoapi/issues/217>`:
All overload signatures are documented.
* `243 <https://github.com/readthedocs/sphinx-autoapi/issues/243>`:
Files are found in order of preference according to ``autoapi_file_patterns``.
* Added support for Sphinx 3.2.

Bug Fixes
^^^^^^^^^
* `219 <https://github.com/readthedocs/sphinx-autoapi/issues/219>`:
Fixed return types not showing for methods.
* Fixed incorrect formatting of properties on generated method directives.
* Fixed every toctree entry getting added as a new list.
* `234 <https://github.com/readthedocs/sphinx-autoapi/issues/234>`:
Fixed only some entries getting added to the toctree.

Trivial/Internal Changes
^^^^^^^^^^^^^^^^^^^^^^^^
* autoapisummary directive inherits from autosummary for future stability.

Links

• PyPI: https://pypi.org/project/sphinx-autoapi
• Changelog: https://pyup.io/changelogs/sphinx-autoapi/
• Repo: http://github.com/readthedocs/sphinx-autoapi