Crate-smartnow

=================

- Enabled TCP keepalive on socket level and support for setting socket options
when creating the connection. The supported options are:

- ``TCP_KEEPIDLE`` (overriding ``net.ipv4.tcp_keepalive_time``)
- ``TCP_KEEPINTVL`` (overriding ``net.ipv4.tcp_keepalive_intvl``)
- ``TCP_KEEPCNT`` (overriding ``net.ipv4.tcp_keepalive_probes``)

- Propagate connect parameter ``pool_size`` to urllib3 as ``maxsize`` parameter
in order to make the connection pool size configurable.

=================

- Added support for the ``RETURNING`` clause to the SQLAlchemy dialect. This
requires CrateDB 4.2 or greater. In case you use any server side generated
columns in your primary key constraint with earlier CrateDB versions, you can
turn this feature off by passing ``implicit_returning=False`` in the
``create_engine()`` call.

- Added support for ``geo_point`` and ``geo_json`` types to the SQLAlchemy
dialect.

=================

- Upgraded SQLAlchemy support to 1.3.

- Added ``backoff_factor`` in connection to configure retry interval.

- Added official Python 3.8 support.

- Made it so that the SQLAlchemy dialect is now aware of the return type of the
``date_trunc`` function.

- Added driver attribute, as SQLAlchemy relies on interfaces having that string for identification.

=================

- Fixed a bug in the ``CrateLayer`` which caused ``CrateDB`` not to start up,
in case the ``JAVA_HOME`` environment variable was not set.

=================

- Extended the type mapping for SQLAlchemy for the upcoming type name changes
in CrateDB 4.0.

- Added support for Python 3.7 and made that version the recommended one.

=================

- Fixed a resource leak in ``CrateLayer``

- Added ability to specify chunk size when getting a blob from the blob container