Log Message:
letsencrypt.org: update to 5.5.0

=== 5.5.0 (2018-01-31)

* Make Database#copy_table in the postgres adapter handle errors that occur \ 
while processing rows (jeremyevans) (#1470)

* Cache results of changed_columns method in local variables in many places for \ 
better performance (jeremyevans)

* Make modification_detection plugin not break column change detection for new \ 
objects (jeremyevans) (#1468)

* Make pg_range extension set :ruby_default schema value for recognized range \ 
defaults (jeremyevans)

* Make pg_interval extension set :ruby_default schema value for recognized \ 
interval defaults (jeremyevans)

* Make pg_json extension set :callable_default schema value for empty json/jsonb \ 
array/hash defaults (jeremyevans)

* Make pg_inet extension set :ruby_default schema value for recognized inet/cidr \ 
defaults (jeremyevans)

* Make pg_hstore extension set :callable_default schema value for empty hstore \ 
defaults (jeremyevans)

* Make pg_array extension set :callable_default schema value for recognized \ 
empty array defaults (jeremyevans) (#1466)

* Make defaults_setter plugin prefer :callable_default db_schema values over \ 
:ruby_default db_schema values (jeremyevans)

* Add defaults_setter plugin :cache option for caching default values returned \ 
(jeremyevans)

* Freeze string values in hashes returned by Database#schema (jeremyevans)

=== 5.4.0 (2018-01-04)

* Enable fractional seconds in timestamps on DB2 (jeremyevans) (#1463)

* Don't attempt to insert a second time if insert_select runs a query that \ 
doesn't return results, which can happen when triggers are used (jeremyevans)

* Make Dataset#insert_select on PostgreSQL and MSSQL return false instead of nil \ 
if the INSERT query is sent to the database but returns no rows (jeremyevans)

* Add index_caching extension for caching calls to Database#indexes (kenaniah, \ 
jeremyevans) (#1461)

* Allow Database#indexes on SQLite, MSSQL, SQLAnywhere, and DB2 to handle \ 
SQL::Identifier values (jeremyevans)

* Add pg_timestamptz extension for using timestamptz (timestamp with time zone) \ 
as the default timestamp type (jeremyevans)

* Support Sequel.date_{add,sub} :cast option for setting cast type in \ 
date_arithmetic extension (jeremyevans)

* Optimize Database#synchronize implementation on ruby 2.5+ (jeremyevans)

* Add class_table_inheritance plugin :ignore_subclass_columns option \ 
(brianphillips) (#1459)

* Make Dataset#to_xml in xml_serializer work with eager_graphed datasets \ 
(jeremyevans)

* Make Dataset#to_json in json_serializer work with eager_graphed datasets \ 
(jeremyevans)

* Cache Dataset#nullify dataset in the null_dataset extension (chanks) (#1456)

* Add datetime_parse_to_time extension, for parsing timestamp strings without \ 
offsets using DateTime.parse.to_time (jeremyevans) (#1455)

* Add WHERE NULL filter for Dataset#where calls with no existing filter, no \ 
argument, and where the virtual row block returns nil (jeremyevans)