Bump version of bcrypt gem
Remove inclusion of rubysl gem for rbx on generated Gemfile

From #14026:

    Specific rbx-2 to limit testing on Rubinius 2.x (since there will be
    other versions of Rubinius > 2.x soon).

    Also, as of Rubinius 2.2.5, it is no longer necessary to bundle the
    rubysl gem.

This is what Rails master/4.1 supports, so we don't need to add rubysl to
gemfiles anymore.
Merge pull request #14149 from tjschuck/bcrypt_gem_rename

Bump version of bcrypt gem
test case for custom PostgreSQL enum type.

This test currently outputs the following warning:

```
unknown OID: current_mood(3567879) (SELECT  "postgresql_enums".* FROM "postgresql_enums"   ORDER BY "postgresql_enums"."id" ASC LIMIT 1)
unknown OID: current_mood(3567879) (SELECT  "postgresql_enums".* FROM "postgresql_enums"  WHERE "postgresql_enums"."id" = $1 LIMIT 1)
```

We have an open PR to deal with this issue. It will dynamically
register the OID for enum columns. This test case is merely to exhibit
the current behavior of PostgreSQL enum columns.
[ci skip] remove guide section on models in migrations

Both examples given are incorrect, and no one can seem to come up with
a realistic situation where this is an actual problem. For now, it seems like
the best thing to do is just scrap the section altogether.
Merge pull request #14208 from lukesteensen/remove-migration-example

[ci skip] remove guide section on models in migrations [ci skip]
move PostgreSQL UUID tests from `datatype_test.rb` to `uuid_test.rb`.
extract common code in `uuid_test.rb`.
[ci skip] Move association class method notes

Make explanation of association class methods clearer by moving notes to beginning of each example section.
Merge pull request #14211 from loganhasson/master

[ci skip] Move association class method notes