Update sqlalchemy to 1.3.21

[pyup-bot]

This PR updates SQLAlchemy from 1.3.20 to 1.3.21.

Changelog

1.3.21

:released: December 17, 2020

 .. change::
     :tags: bug, orm
     :tickets: 5774
     :versions: 1.4.0b2

     Added a comprehensive check and an informative error message for the case
     where a mapped class, or a string mapped class name, is passed to
     :paramref:`_orm.relationship.secondary`.  This is an extremely common error
     which warrants a clear message.

     Additionally, added a new rule to the class registry resolution such that
     with regards to the :paramref:`_orm.relationship.secondary` parameter, if a
     mapped class and its table are of the identical string name, the
     :class:`.Table` will be favored when resolving this parameter.   In all
     other cases, the class continues to be favored if a class and table
     share the identical name.

 .. change::
     :tags: sqlite, usecase
     :tickets: 5685

     Added ``sqlite_with_rowid=False`` dialect keyword to enable creating
     tables as ``CREATE TABLE … WITHOUT ROWID``. Patch courtesy Sean Anderson.

 .. change::
     :tags: bug, sql
     :tickets: 5691

     A warning is emmitted if a returning() method such as
     :meth:`_sql.Insert.returning` is called multiple times, as this does not
     yet support additive operation.  Version 1.4 will support additive
     operation for this.  Additionally, any combination of the
     :meth:`_sql.Insert.returning` and :meth:`_sql.ValuesBase.return_defaults`
     methods now raises an error as these methods are mutually exclusive;
     previously the operation would fail silently.


 .. change::
     :tags: bug, mssql
     :tickets: 5751

     Fixed bug where a CREATE INDEX statement was rendered incorrectly when
     both ``mssql-include`` and ``mssql_where`` were specified. Pull request
     courtesy Adiorz.

 .. change::
     :tags: bug, postgresql, mysql
     :tickets: 5729
     :versions: 1.4.0b2

     Fixed regression introduced in 1.3.2 for the PostgreSQL dialect, also
     copied out to the MySQL dialect's feature in 1.3.18, where usage of a non
     :class:`_schema.Table` construct such as :func:`_sql.text` as the argument
     to :paramref:`_sql.Select.with_for_update.of` would fail to be accommodated
     correctly within the PostgreSQL or MySQL compilers.


 .. change::
     :tags: bug, mssql
     :tickets: 5646

     Added SQL Server code "01000" to the list of disconnect codes.


 .. change::
     :tags: usecase, postgresql
     :tickets: 5604
     :versions: 1.4.0b2

     Added new parameter :paramref:`_postgresql.ExcludeConstraint.ops` to the
     :class:`_postgresql.ExcludeConstraint` object, to support operator class
     specification with this constraint.  Pull request courtesy Alon Menczer.

 .. change::
     :tags: bug, mysql, reflection
     :tickets: 5744
     :versions: 1.4.0b2

     Fixed issue where reflecting a server default on MariaDB only that
     contained a decimal point in the value would fail to be reflected
     correctly, leading towards a reflected table that lacked any server
     default.


 .. change::
     :tags: bug, orm
     :tickets: 5664

     Fixed bug in :meth:`_query.Query.update` where objects in the
     :class:`_ormsession.Session` that were already expired would be
     unnecessarily SELECTed individually when they were refreshed by the
     "evaluate"synchronize strategy.

 .. change::
     :tags: usecase, oracle
     :tickets: 5755

     Implemented support for the SERIALIZABLE isolation level for Oracle
     databases, as well as a real implementation for
     :meth:`_engine.Connection.get_isolation_level`.

     .. seealso::

         :ref:`oracle_isolation_level`

 .. change::
     :tags: mysql, sql
     :tickets: 5696

     Added missing keywords to the ``RESERVED_WORDS`` list for the MySQL
     dialect: ``action``, ``level``, ``mode``, ``status``, ``text``, ``time``.
     Pull request courtesy Oscar Batori.

 .. change::
     :tags: bug, orm
     :tickets: 5737
     :versions: 1.4.0b2

     Fixed bug involving the ``restore_load_context`` option of ORM events such
     as :meth:`_ormevent.InstanceEvents.load` such that the flag would not be
     carried along to subclasses which were mapped after the event handler were
     first established.



 .. change::
     :tags: bug, sql
     :tickets: 5656

     Fixed structural compiler issue where some constructs such as MySQL /
     PostgreSQL "on conflict / on duplicate key" would rely upon the state of
     the :class:`_sql.Compiler` object being fixed against their statement as
     the top level statement, which would fail in cases where those statements
     are branched from a different context, such as a DDL construct linked to a
     SQL statement.


 .. change::
     :tags: mssql, sqlite, reflection
     :tickets: 5661

     Fixed issue with composite primary key columns not being reported
     in the correct order. Patch courtesy fulpm.

.. changelog::

Links

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

[coveralls]

Coverage remained the same at 86.667% when pulling 38b013c on pyup-update-sqlalchemy-1.3.20-to-1.3.21 into ecb9b8f on master.

[pyup-bot]

Closing this in favor of #238