Add Rails 5.2 build (scenic-views#257)

* Update Appraisals and regenerate, to match changes in scenic-views#232
* Update required Ruby version to match discussion in scenic-views#232
* Add Rails 5.2 to Appraisals
* Add Rails 5.2 to Travis config
* Add 'ApplicationRecord' to fix generated models on 5.0+

.travis.yml

@@ -25,6 +25,7 @@ gemfile:
   - gemfiles/rails42.gemfile
   - gemfiles/rails50.gemfile
   - gemfiles/rails51.gemfile
+  - gemfiles/rails52.gemfile
   - gemfiles/rails_edge.gemfile
 matrix:
   allow_failures:

Appraisals

@@ -1,33 +1,24 @@
-if RUBY_VERSION < "2.4.0"
-  appraise "rails40" do
-    gem "activerecord", "~> 4.0.0"
-    gem "railties", "~> 4.0.0"
-  end
-
-  appraise "rails41" do
-    gem "activerecord", "~> 4.1.0"
-    gem "railties", "~> 4.1.0"
-  end
-end
-
 appraise "rails42" do
   gem "activerecord", "~> 4.2.0"
   gem "railties", "~> 4.2.0"
 end
 
-if RUBY_VERSION > "2.2.0"
-  appraise "rails50" do
-    gem "activerecord", "~> 5.0.0"
-    gem "railties", "~> 5.0.0"
-  end
+appraise "rails50" do
+  gem "activerecord", "~> 5.0.0"
+  gem "railties", "~> 5.0.0"
+end
 
-  appraise "rails51" do
-    gem "activerecord", "~> 5.1.0"
-    gem "railties", "~> 5.1.0"
-  end
+appraise "rails51" do
+  gem "activerecord", "~> 5.1.0"
+  gem "railties", "~> 5.1.0"
+end
+
+appraise "rails52" do
+  gem "activerecord", "~> 5.2.0"
+  gem "railties", "~> 5.2.0"
+end
 
-  appraise "rails-edge" do
-    gem "rails", git: "https://github.com/rails/rails"
-    gem "arel", git: "https://github.com/rails/arel"
-  end
+appraise "rails-edge" do
+  gem "rails", git: "https://github.com/rails/rails"
+  gem "arel", git: "https://github.com/rails/arel"
 end

gemfiles/rails52.gemfile

@@ -0,0 +1,8 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "activerecord", "~> 5.2.0"
+gem "railties", "~> 5.2.0"
+
+gemspec path: "../"

scenic.gemspec

@@ -34,5 +34,5 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'activerecord', '>= 4.0.0'
   spec.add_dependency 'railties', '>= 4.0.0'
 
-  spec.required_ruby_version = '~> 2.1'
+  spec.required_ruby_version = '>= 2.3.0'
 end

spec/dummy/app/models/application_record.rb

@@ -0,0 +1,5 @@
+if Rails::VERSION::STRING >= "5.0.0"
+  class ApplicationRecord < ActiveRecord::Base
+    self.abstract_class = true
+  end
+end