FEATURE: Make it easier to localize "email has been taken"
Rebuild Gemfile_master.lock based on the lastest Gemfile.lock
actionpack-action_caching was released a long time ago
Use Rails 4.2+ API for typecasting on master

Note: this is still considered a private (internal) API on Rails side and is
subject to change in the future.
Boolean -> String quoting has changed on Rails master

CustomField.create(name: 'zomg', value: true).reload.value # => 't' on Rails 4.1, '1' on 4.2

rails/rails@42be84ba
Avoid a deprecation warning by poly-filling #deliver_now and #deliver_now
HAX: force the lazy `MessageDelivery` object to create the mailer

Starting from Rails 4.2, calling MyMailer.some_method no longer result in an
immediate call to MyMailer#some_method. Instead, a "lazy proxy" is returned
(this is changed to support #deliver_later). As a quick hack to fix the test,
calling #message (or anything, really) would force the Mailer object to be
created and the method invoked.
Fix an PG overflow problem

In 4.2.0+, `#find_by` switched to using (cached!) prepared statements. As a side-
effect, doing out-of-range queries like `Topic.find_by(id: '9999999999999999999999999999')`
causes PG to complain instead of returning 0 rows. (Differece between sending
the literal 9999999999999999999 in a query and the quoted "9999999999999999999",
apparently.) Rescusing it for now, althought it might somehow be fixed upstream
in the future.
`Sprockets::Context` takes a `Pathname` for its third argument

Not sure what actually changed and why it was working before, but it now throws
a `NoMethodError` for `dirname` on `String` in `Context#resolve`
Use *_url instead of *_path to avoid a deprecation warning
HAX: check the `message` object, not the `MessageDelivery` object

See 669bf73 for background. It's probably better to rewrite these test without
using the internal `NullMail` class anyway.
rails-dom-testing <= 1.0.3 broke application controller specs (#20)