Fixed `columns_for_distinct` of postgresql adapter
pg, `PostgreSQL::Name` to hold schema qualified names.
pg, `reset_pk_sequence!` respects schemas. Closes #14719.
`bin/setup` script to bootstrap applications.
Merge pull request #15189 from senny/bin/setup

`bin/setup` script to bootstrap applications.
:scissors: removed deprecated `Numeric#ago` and friends

Replacements:

   5.ago   => 5.seconds.ago
   5.until => 5.seconds.until
   5.since => 5.seconds.since
   5.from_now => 5.seconds.from_now

The removed tests does not affect coverage – we have equivalent test cases in
the tests for `AS::Duration`.

See #12389 for the history and rationale behind this.
Merge pull request #11896 from nkondratyev/fix_pg_columns_for_distinct

Fixed #columns_for_distinct of postgresql adapter

Conflicts:
	activerecord/CHANGELOG.md
pg, `default_sequence_name` respects schema. Closes #7516.
pg, support default values for enum types. Closes #7814.

This is an intermediate solution. It is related to the refactoring @sgrif
is making and will change in the future.
refactor, introduce `Type#type_cast_for_schema` to cast for schema.rb

This removes the case statement in `SchemaDumper` and gives every `Type`
the possibility to control the SchemaDumper default value output.

/cc @sgrif