Add Rails master to Travis, fix specs for 5.2

.travis.yml

@@ -15,12 +15,15 @@ gemfile:
   - gemfiles/rails_4_2.gemfile
   - gemfiles/rails_5_0.gemfile
   - gemfiles/rails_5_1.gemfile
+  - gemfiles/rails_master.gemfile
 
 matrix:
   exclude:
     - gemfile: gemfiles/rails_5_0.gemfile
       rvm: 2.1
     - gemfile: gemfiles/rails_5_1.gemfile
       rvm: 2.1
+    - gemfile: gemfiles/rails_master.gemfile
+      rvm: 2.1
   allowed_failures:
-    - gemfile: gemfiles/rails_5_1.gemfile
+    - gemfile: gemfiles/rails_master.gemfile

gemfiles/rails_5_1.gemfile

@@ -7,7 +7,6 @@ gem "appraisal"
 gem "activerecord-jdbcsqlite3-adapter", :platform => :jruby
 gem "sqlite3", :platform => [:ruby, :mswin, :mingw, :x64_mingw]
 gem "tzinfo-data", :platforms => [:mingw, :mswin, :x64_mingw]
-gem "arel", :github => "rails/arel"
-gem "rspec-rails", "~> 3.5"
+gem "rspec-rails", "~> 3.7"
 
 gemspec :path => "../"

gemfiles/rails_master.gemfile

@@ -0,0 +1,13 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", git: 'https://github.com/rails/rails'
+gem "arel", git: 'https://github.com/rails/arel'
+gem "appraisal"
+gem "activerecord-jdbcsqlite3-adapter", platform: :jruby
+gem "sqlite3", platform: [:ruby, :mswin, :mingw, :x64_mingw]
+gem "tzinfo-data", platforms: [:mingw, :mswin, :x64_mingw]
+gem "rspec-rails", "~> 3.7"
+
+gemspec :path => "../"

spec/requests/endpoints/token_spec.rb

@@ -9,7 +9,14 @@
   it 'respond with correct headers' do
     post token_endpoint_url(code: @authorization.token, client: @client)
     should_have_header 'Pragma', 'no-cache'
-    should_have_header 'Cache-Control', 'no-store'
+
+    # Rails 5.2 changed headers
+    if ::Rails::VERSION::MAJOR >= 5 && ::Rails::VERSION::MINOR >= 2
+      should_have_header 'Cache-Control', 'private, no-store'
+    else
+      should_have_header 'Cache-Control', 'no-store'
+    end
+
     should_have_header 'Content-Type', 'application/json; charset=utf-8'
   end