Fixed a problem where `sum`, `size`, `average`, `minimum` and `maximum` used
with a grouping was not returning a Hash.
Rename Posts to Articles in Guides, continuation of 2d446e77 / #13774 [ci skip]
Merge pull request #15215 from JohnKellyFerguson/rename-posts-to-articles

Documentation: Rename Posts to Articles
Update CHANGELOG.md

Most recent change should be moved to the top
Merge pull request #14803 from kuldeepaggarwal/null_relation_sum_fix

Fixed a problem where `sum` used with a `group` was not returning a Hash.
Form full URI as string to be parsed in Rack::Test.

There are performance gains to be made by avoiding URI setter methods.
Merge pull request #15101 from tgxworld/improve_performance_of_building_uri

Form full URI as string to be parsed in Rack::Test.
pg test, remove unused code.
pg test, extract network address type tests into separate file.
pg test, move timestamp tests over to `postgresql/timestamp_test.rb`.
pg test, extract tsvector tests into `postgresql/full_text_test.rb`