Allow custom asset host to be passed in asset_url
Improve documentation for asset_url

Updated CHANGELOG.md with entry about :host in asset_url
formatting pass through CHANGELOGS. [ci skip]
fixed a typo [ci skip]
Merge pull request #15133 from ShunsukeAida/master

fixed a typo
Document conflicts in `db/schema.rb` [ci skip]
Merge pull request #15113 from leafac/document-schema-conflicts

Document conflicts in `db/schema.rb` [ci skip]
Our test suite isn't ready to run in random order yet :cry:
Merge pull request #15021 from hubertlepicki/allow_custom_host_in_asset_url

Allow custom asset host to be passed in asset_url
Form full URI as string to be parsed in Rack::Test.

There is performance gains to be made by avoiding URI setter methods.