Tests can be run on PostgreSQL now

gemfiles/active_record_41.gemfile

@@ -10,9 +10,11 @@ platforms :ruby do
     gem 'sqlite3', '1.3.8'
     gem 'nokogiri', '~> 1.6.8'
   end
+  gem 'pg'
 end
 platforms :jruby do
   gem 'activerecord-jdbcsqlite3-adapter', '>= 1.3.0'
+  gem 'activerecord-jdbcpostgresql-adapter'
 end
 platforms :rbx do
   gem 'rubysl', '~> 2.0'

gemfiles/active_record_42.gemfile

@@ -10,9 +10,11 @@ platforms :ruby do
     gem 'sqlite3', '1.3.8'
     gem 'nokogiri', '~> 1.6.8'
   end
+  gem 'pg'
 end
 platforms :jruby do
   gem 'activerecord-jdbcsqlite3-adapter', '>= 1.3.0'
+  gem 'activerecord-jdbcpostgresql-adapter'
 end
 platforms :rbx do
   gem 'rubysl', '~> 2.0'

gemfiles/active_record_50.gemfile

@@ -6,9 +6,11 @@ gem 'actionview', '~> 5.0.0', require: 'action_view'
 
 platforms :ruby do
   gem 'sqlite3'
+  gem 'pg'
 end
 platforms :jruby do
   gem 'activerecord-jdbcsqlite3-adapter', '>= 1.3.0'
+  gem 'activerecord-jdbcpostgresql-adapter'
 end
 platforms :rbx do
   gem 'rubysl', '~> 2.0'

gemfiles/active_record_51.gemfile

@@ -6,9 +6,11 @@ gem 'actionview', '~> 5.1.0', require: 'action_view'
 
 platforms :ruby do
   gem 'sqlite3'
+  gem 'pg'
 end
 platforms :jruby do
   gem 'activerecord-jdbcsqlite3-adapter', '>= 1.3.0'
+  gem 'activerecord-jdbcpostgresql-adapter'
 end
 platforms :rbx do
   gem 'rubysl', '~> 2.0'

kaminari-core/test/fake_app/config/database.yml

@@ -4,5 +4,12 @@ sqlite3: &sqlite3
   pool: 5
   timeout: 5000
 
+postgresql: &postgresql
+  adapter: postgresql
+  host: localhost
+  username: postgres
+  password:
+  database: kaminari_test
+
 test:
   <<: *<%= ENV['DB'] %>