Log Message:
databases/ruby-sequel: update to 5.2.0

=== 5.2.0 (2017-10-27)

* Fix type conversion for smallint unsigned and integer unsigned types on
  jdbc/mysql (jeremyevans) (#1443)

* Add pg_extended_date_support extension, for handling infinite and BC
  dates/timestamps (jeremyevans)

* Do not ignore existing @dataset instance variable when subclassing
  Sequel::Model (bjmllr) (#1435)

=== 5.1.0 (2017-10-01)

* Make jdbc/h2 and jdbc/hsqldb adapters respect :foreign_key_constraint_name
  option when adding new foreign key column (jeremyevans)

* Do not issue unnecessary query for macaddr type oid when loading the pg_inet
  extension (jeltz) (#1423)

* Make alter_table add_foreign_key with a column symbol reversible when using
  the :foreign_key_constraint_name option (jeremyevans) (#1422)

* Do not raise an error if calling Model.freeze on a frozen model
  (jeremyevans) (#1421)

* Make Database#copy_into in the jdbc/postgresql adapter handle multi-byte
  strings (ckoenig) (#1416)

* Remove deprecated Model use_after_commit_rollback class and instance methods
  (jeremyevans)

* Remove deprecated Model.allowed_columns method in the base model support
  (jeremyevans)

* Remove deprecated Model.plugin_module_defined? private method (jeremyevans)

* Remove deprecated support for Model#_before_validation private method
  (jeremyevans)