[Backend Dependencies Update] Update sqlalchemy to 1.3.4

[pyup-bot]

This PR updates SQLAlchemy from 1.3.3 to 1.3.4.

Changelog

1.3.4

:released: May 27, 2019

 .. change::
     :tags: feature, mssql
     :tickets: 4657

     Added support for SQL Server filtered indexes, via the ``mssql_where``
     parameter which works similarly to that of the ``postgresql_where`` index
     function in the PostgreSQL dialect.

     .. seealso::

         :ref:`mssql_index_where`

 .. change::
    :tags: bug, misc
    :tickets: 4625

    Removed errant "sqla_nose.py" symbol from MANIFEST.in which created an
    undesirable warning message.

 .. change::
     :tags: bug, sql
     :tickets: 4653

     Fixed that the :class:`.GenericFunction` class was inadvertently
     registering itself as one of the named functions.  Pull request courtesy
     Adrien Berchet.

 .. change::
    :tags: bug, engine, postgresql
    :tickets: 4663

    Moved the "rollback" which occurs during dialect initialization so that it
    occurs after additional dialect-specific initialize steps, in particular
    those of the psycopg2 dialect which would inadvertently leave transactional
    state on the first new connection, which could interfere with some
    psycopg2-specific APIs which require that no transaction is started.  Pull
    request courtesy Matthew Wilkes.


 .. change::
     :tags: bug, orm
     :tickets: 4695

     Fixed issue where the :paramref:`.AttributeEvents.active_history` flag
     would not be set for an event listener that propgated to a subclass via the
     :paramref:`.AttributeEvents.propagate` flag.   This bug has been present
     for the full span of the :class:`.AttributeEvents` system.


 .. change::
     :tags: bug, orm
     :tickets: 4690

     Fixed regression where new association proxy system was still not proxying
     hybrid attributes when they made use of the ``hybrid_property.expression``
     decorator to return an alternate SQL expression, or when the hybrid
     returned an arbitrary :class:`.PropComparator`, at the expression level.
     This involved futher generalization of the heuristics used to detect the
     type of object being proxied at the level of :class:`.QueryableAttribute`,
     to better detect if the descriptor ultimately serves mapped classes or
     column expressions.

 .. change::
     :tags: bug, orm
     :tickets: 4686

     Applied the mapper "configure mutex" against the declarative class mapping
     process, to guard against the race which can occur if mappers are used
     while dynamic module import schemes are still in the process of configuring
     mappers for related classes.  This does not guard against all possible race
     conditions, such as if the concurrent import has not yet encountered the
     dependent classes as of yet, however it guards against as much as possible
     within the SQLAlchemy declarative process.

 .. change::
     :tags: bug, mssql
     :tickets: 4680

     Added error code 20047 to "is_disconnect" for pymssql.  Pull request
     courtesy Jon Schuff.


 .. change::
    :tags: bug, postgresql, orm
    :tickets: 4661

    Fixed an issue where the "number of rows matched" warning would emit even if
    the dialect reported "supports_sane_multi_rowcount=False", as is the case
    for psycogp2 with ``use_batch_mode=True`` and others.


 .. change::
     :tags: bug, sql
     :tickets: 4618

     Fixed issue where double negation of a boolean column wouldn't reset
     the "NOT" operator.

 .. change::
     :tags: mysql, bug
     :tickets: 4650

     Added support for DROP CHECK constraint which is required by MySQL 8.0.16
     to drop a CHECK constraint; MariaDB supports plain DROP CONSTRAINT.  The
     logic distinguishes between the two syntaxes by checking the server version
     string for MariaDB presence.    Alembic migrations has already worked
     around this issue by implementing its own DROP for MySQL / MariaDB CHECK
     constraints, however this change implements it straight in Core so that its
     available for general use.   Pull request courtesy Hannes Hansen.

 .. change::
    :tags: bug, orm
    :tickets: 4647

    A warning is now emitted for the case where a transient object is being
    merged into the session with :meth:`.Session.merge` when that object is
    already transient in the :class:`.Session`.   This warns for the case where
    the object would normally be double-inserted.


 .. change::
     :tags: bug, orm
     :tickets: 4676

     Fixed regression in new relationship m2o comparison logic first introduced
     at :ref:`change_4359` when comparing to an attribute that is persisted as
     NULL and is in an un-fetched state in the mapped instance.  Since the
     attribute has no explicit default, it needs to default to NULL when
     accessed in a persistent setting.


 .. change::
     :tags: bug, sql
     :tickets: 4569

     The :class:`.GenericFunction` namespace is being migrated so that function
     names are looked up in a case-insensitive manner, as SQL  functions do not
     collide on case sensitive differences nor is this something which would
     occur with user-defined functions or stored procedures.   Lookups for
     functions declared with :class:`.GenericFunction` now use a case
     insensitive scheme,  however a deprecation case is supported which allows
     two or more :class:`.GenericFunction` objects with the same name of
     different cases to exist, which will cause case sensitive lookups to occur
     for that particular name, while emitting a warning at function registration
     time.  Thanks to Adrien Berchet for a lot of work on this complicated
     feature.


.. changelog::

Links

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

[pyup-bot]

Closing this in favor of #679