active_record: Quote numeric values compared to string columns.

Travis failed because the postgresql version installed there does not
support extensions, so we just need to skip this for now.

There is no need to create the extension in the database just to test if
it's dumped, we can stub that instead.

When extensions are supported but there's no one enabled in the
database, we should not print anything related to them in schema.rb.

[ci skip]

Adding database extension support to schema.rb

add ActiveRecord::AbstractAdapter#extensions and ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#extensions to allow dumping of enabled extensions to schema.rb, add ActiveRecord::SchemaDumper#extensions to dump extensions to schema.rb

improve tests to check for existence of extensions method, and skip testing dumped extensions if they are unsupported by the database

And improve AS changelog a bit [ci skip]

Modify TimeWithZone#as_json to return 3DP of sub-second accuracy.

[ci skip]

ruby constant syntax is not supported as routing `:controller` option.

The current implementation only works correctly if you supply the `:controller`
with directory notation (eg. `:controller => 'admin/posts'`).

The ruby constant notation (eg. `:controller => 'Admin::Posts`) leads to unexpected problems with `url_for`.

This patch prints a warning for every non supported `:controller` option. I also added documentation how
to work with namespaced controllers. The warning links to that documentation in the rails guide.

Get rid of old .rvmrc and .rbenv-version files.

Ignore .ruby-version

Update upgrading guide with ActionDispatch::BestStandardsSupport removal [ci skip]

Added test:all and test:all:db tasks to speed up full test runs

Speed up depends on the number of test phases (N) you have for your
app, but it is roughly a 1/N improvement. In my app, it goes from
15.51s to 5.56s.

Inspired by http://ngauthier.com/2012/02/quick-tests-with-bash.html

Reviewed by @tenderlove

Add --rc description on the command line

Use --rc=PATH instead of --rc PATH

Improved `assert_template` when matching :locals with partials

previously when a partial was placed inside a directory
(eg. '/dir/_partial'), `assert_template` did not replace
the '_' prefix when looking through rendered tempaltes,
which resulted in an error.

I modified it to replace both, the leading '_' and the last '_'
after a '/'.

When `assert_template` is used with the :locals option, and the
partial was not rendered, a method_missing error was raised.
This changes first checks, if the partial actually was rendered
and raises a descriptive error.

test for issue 8931

Put .rdoc at the end of the files named RUNNING_UNIT_TESTS

So that they are printed nicely on GitHub.

Add --no-rc description on the command line

Fix link to point to new RefineryCMS repo