Fix CI on 0-10-stable (#2181)

* Loosen pry, pry-byebug depencency

```
Resolving dependencies...
byebug-9.1.0 requires ruby version >= 2.2.0, which is
incompatible with the current version, ruby 2.1.10p492
```

* Adjust nokogiri version constraint for CI

Update appveyor Ruby to 2.3 to work around:

```
Gem::InstallError: nokogiri requires Ruby version < 2.5, >= 2.2.

An error occurred while installing nokogiri (1.8.0), and Bundler cannot continue.
Make sure that `gem install nokogiri -v '1.8.0'` succeeds before bundling.
```

and not 2.4 since:

https://ci.appveyor.com/project/bf4/active-model-serializers/build/1.0.1052-fix_ci/job/0q3itabsnvnxr83u

```
nokogiri-1.6.8.1-x86-mingw32 requires ruby version < 2.4, which is incompatible with the current version, ruby 2.4.1p111
```

* Include rails gem in Gemfile

(For Rails5)

In Rails5, checking for Rails::Railtie is better

* Rails5 test env requires Rails.application.class.name

rails-42d09f6b49da/railties/lib/rails/application.rb

```ruby
def secret_key_base
  if Rails.env.test? || Rails.env.development?
  Digest::MD5.hexdigest self.class.name
```

* Reformat exclude matrix to be easier to read

* Simplify jruby-travis config per rails/rails

* Organize .travis.yml per rails/rails

* Allow JRuby failure on Rails 5+; try rails-5 db adapter branch

https://github.com/jruby/activerecord-jdbc-adapter/issues/708

```
uninitialized constant ActiveRecord::ConnectionAdapters::Column::Format
```

see https://travis-ci.org/rails-api/active_model_serializers/jobs/277112008

.travis.yml

@@ -1,55 +1,47 @@
 language: ruby
-
 sudo: false
 
-rvm:
-  - 2.1
-  - 2.2.6
-  - 2.3.3
-  - ruby-head
-  - jruby-9.1.5.0 # is precompiled per http://rubies.travis-ci.org/
-  - jruby-head
-
-jdk:
-  - oraclejdk8
-
-before_install:
-  - gem update --system
-  - rvm @global do gem uninstall bundler -a -x
-  - rvm @global do gem install bundler -v 1.13.7
-install: bundle install --path=vendor/bundle --retry=3 --jobs=3
 cache:
   directories:
     - vendor/bundle
 
+before_install:
+  - "travis_retry gem update --system"
+  - "travis_retry gem update bundler"
+install: bundle install --path=vendor/bundle --retry=3 --jobs=3
+
 script:
   - bundle exec rake ci
 after_success:
   - codeclimate-test-reporter
+
 env:
-  global:
-    - "JRUBY_OPTS='--dev -J-Xmx1024M --debug'"
   matrix:
     - "RAILS_VERSION=4.1"
     - "RAILS_VERSION=4.2"
     - "RAILS_VERSION=5.0"
     - "RAILS_VERSION=master"
 
+rvm:
+  - 2.1
+  - 2.2.6
+  - 2.3.3
+  - ruby-head
+
 matrix:
+  include:
+  - { rvm: jruby-9.1.13.0, jdk: oraclejdk8, env: "RAILS_VERSION=4.1 JRUBY_OPTS='--dev -J-Xmx1024M --debug'" }
+  - { rvm: jruby-9.1.13.0, jdk: oraclejdk8, env: "RAILS_VERSION=4.2 JRUBY_OPTS='--dev -J-Xmx1024M --debug'" }
+  - { rvm: jruby-9.1.13.0, jdk: oraclejdk8, env: "RAILS_VERSION=5.1 JRUBY_OPTS='--dev -J-Xmx1024M --debug'" }
+  # See JRuby currently failing on Rails 5+ https://github.com/jruby/activerecord-jdbc-adapter/issues/708
+  # - { rvm: jruby-9.1.13.0, jdk: oraclejdk8, env: "RAILS_VERSION=5.0 JRUBY_OPTS='--dev -J-Xmx1024M --debug'" }
+  # - { rvm: jruby-head,     jdk: oraclejdk8, env: "RAILS_VERSION=5.1 JRUBY_OPTS='--dev -J-Xmx1024M --debug'" }
   exclude:
-  - rvm: 2.1
-    env: RAILS_VERSION=master
-  - rvm: jruby-9.1.5.0
-    env: RAILS_VERSION=master
-  - rvm: jruby-head
-    env: RAILS_VERSION=master
-  - rvm: 2.1
-    env: RAILS_VERSION=5.0
-  - rvm: jruby-9.1.5.0
-    env: RAILS_VERSION=5.0
-  - rvm: jruby-head
-    env: RAILS_VERSION=5.0
+  - { rvm: 2.1,           env: RAILS_VERSION=master }
+  - { rvm: 2.1,           env: RAILS_VERSION=5.0 }
   allow_failures:
     - rvm: ruby-head
     - rvm: jruby-head
+    # See JRuby currently failing on Rails 5+ https://github.com/jruby/activerecord-jdbc-adapter/issues/708
+    - { rvm: jruby-9.1.13.0, jdk: oraclejdk8, env: "RAILS_VERSION=5.1 JRUBY_OPTS='--dev -J-Xmx1024M --debug'" }
   fast_finish: true

Gemfile

@@ -12,6 +12,7 @@ version = ENV['RAILS_VERSION'] || '4.2'
 if version == 'master'
   gem 'rack', github: 'rack/rack'
   gem 'arel', github: 'rails/arel'
+  gem 'rails', github: 'rails/rails'
   git 'https://github.com/rails/rails.git' do
     gem 'railties'
     gem 'activesupport'
@@ -23,6 +24,7 @@ if version == 'master'
   end
 else
   gem_version = "~> #{version}.0"
+  gem 'rails', gem_version
   gem 'railties', gem_version
   gem 'activesupport', gem_version
   gem 'activemodel', gem_version
@@ -36,18 +38,32 @@ end
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: (@windows_platforms + [:jruby])
 
+if ENV['CI']
+  if RUBY_VERSION < '2.4'
+    # Windows: An error occurred while installing nokogiri (1.8.0)
+    gem 'nokogiri', '< 1.7', platforms: @windows_platforms
+  end
+end
+
 group :bench do
   # https://github.com/rails-api/active_model_serializers/commit/cb4459580a6f4f37f629bf3185a5224c8624ca76
   gem 'benchmark-ips', '>= 2.7.2', require: false, group: :development
 end
 
 group :test do
-  gem 'sqlite3',                          platform: (@windows_platforms + [:ruby])
-  gem 'activerecord-jdbcsqlite3-adapter', platform: :jruby
+  gem 'sqlite3', platform: (@windows_platforms + [:ruby])
+  platforms :jruby do
+    if version == 'master' || version >= '5'
+      gem 'activerecord-jdbcsqlite3-adapter', github: 'jruby/activerecord-jdbc-adapter', branch: 'rails-5'
+    else
+      gem 'activerecord-jdbcsqlite3-adapter'
+    end
+  end
   gem 'codeclimate-test-reporter', require: false
   gem 'm', '~> 1.5'
-  gem 'pry', '~> 0.10'
-  gem 'pry-byebug', '~> 3.4', platform: :ruby
+  gem 'pry', '>= 0.10'
+  gem 'byebug', '~> 8.2' if RUBY_VERSION < '2.2'
+  gem 'pry-byebug', platform: :ruby
 end
 
 group :development, :test do

appveyor.yml

@@ -5,8 +5,8 @@ skip_tags: true
 environment:
   JRUBY_OPTS: "--dev -J-Xmx1024M --debug"
   matrix:
-    - ruby_version: "Ruby21"
-    - ruby_version: "Ruby21-x64"
+    - ruby_version: "Ruby23"
+    - ruby_version: "Ruby23-x64"
 
 cache:
   - vendor/bundle

lib/active_model_serializers.rb

@@ -49,5 +49,5 @@ module ActiveModelSerializers
   require 'active_model/serializer/version'
   require 'active_model/serializer'
   require 'active_model/serializable_resource'
-  require 'active_model_serializers/railtie' if defined?(::Rails)
+  require 'active_model_serializers/railtie' if defined?(::Rails::Railtie)
 end

test/support/isolated_unit.rb

@@ -54,7 +54,7 @@ module TestHelpers
       require 'rails'
       require 'action_controller/railtie'
 
-      @app = Class.new(Rails::Application) do
+      app = Class.new(Rails::Application) do
         config.eager_load = false
         config.session_store :cookie_store, key: '_myapp_session'
         config.active_support.deprecation = :log
@@ -67,8 +67,10 @@ module TestHelpers
         config.logger = fake_logger
         Rails.application.routes.default_url_options = { host: 'example.com' }
       end
-      @app.respond_to?(:secrets) && @app.secrets.secret_key_base = '3b7cd727ee24e8444053437c36cc66c4'
+      def app.name; 'IsolatedRailsApp'; end # rubocop:disable Style/SingleLineMethods
+      app.respond_to?(:secrets) && app.secrets.secret_key_base = '3b7cd727ee24e8444053437c36cc66c4'
 
+      @app = app
       yield @app if block_given?
       @app.initialize!
     end