Bump to Rails 4.2.0 as that's the most recently supported Rails version

This solves issues with json 1.8.3 not compiling against Ruby 2.4.1 etc.

Author: David Heinemeier Hansson

Appraisals

@@ -1,36 +1,3 @@
-appraise "rails-3-0" do
-  gem "test-unit"
-  gem "railties",    "~> 3.0.0"
-  gem "actionpack",  "~> 3.0.0"
-  gem "activemodel", "~> 3.0.0"
-end
-
-appraise "rails-3-1" do
-  gem "test-unit"
-  gem "railties",    "~> 3.1.0"
-  gem "actionpack",  "~> 3.1.0"
-  gem "activemodel", "~> 3.1.0"
-end
-
-appraise "rails-3-2" do
-  gem "test-unit"
-  gem "railties",    "~> 3.2.0"
-  gem "actionpack",  "~> 3.2.0"
-  gem "activemodel", "~> 3.2.0"
-end
-
-appraise "rails-4-0" do
-  gem "railties",    "~> 4.0.0"
-  gem "actionpack",  "~> 4.0.0"
-  gem "activemodel", "~> 4.0.0"
-end
-
-appraise "rails-4-1" do
-  gem "railties",    "~> 4.1.0"
-  gem "actionpack",  "~> 4.1.0"
-  gem "activemodel", "~> 4.1.0"
-end
-
 appraise "rails-4-2" do
   gem "railties",    "~> 4.2.0"
   gem "actionpack",  "~> 4.2.0"

Rakefile

@@ -12,11 +12,7 @@ else
 
     test.libs << "test"
 
-    if Rails::VERSION::MAJOR == 3
-      test.test_files = %w[test/jbuilder_template_test.rb test/jbuilder_test.rb]
-    else
-      test.test_files = FileList["test/*_test.rb"]
-    end
+    test.test_files = FileList["test/*_test.rb"]
   end
 
   task default: :test

gemfiles/rails_3_0.gemfile

@@ -3,12 +3,11 @@
 source "https://rubygems.org"
 
 gem "rake"
-gem "mocha", :require => false
+gem "mocha", require: false
 gem "appraisal"
 gem "pry"
 gem "railties", "~> 4.2.0"
 gem "actionpack", "~> 4.2.0"
 gem "activemodel", "~> 4.2.0"
-gem "nokogiri", "< 1.7" if RUBY_VERSION < "2.1"
 
-gemspec :path => "../"
+gemspec path: "../"

gemfiles/rails_3_1.gemfile

@@ -3,11 +3,11 @@
 source "https://rubygems.org"
 
 gem "rake"
-gem "mocha", :require => false
+gem "mocha", require: false
 gem "appraisal"
 gem "pry"
 gem "railties", "~> 5.0.0"
 gem "actionpack", "~> 5.0.0"
 gem "activemodel", "~> 5.0.0"
 
-gemspec :path => "../"
+gemspec path: "../"

gemfiles/rails_3_2.gemfile

@@ -3,11 +3,11 @@
 source "https://rubygems.org"
 
 gem "rake"
-gem "mocha", :require => false
+gem "mocha", require: false
 gem "appraisal"
 gem "pry"
 gem "railties", ">= 5.1.0", "< 5.2"
 gem "actionpack", ">= 5.1.0", "< 5.2"
 gem "activemodel", ">= 5.1.0", "< 5.2"
 
-gemspec :path => "../"
+gemspec path: "../"