Update travis configuration

.travis.yml

@@ -14,8 +14,10 @@ rvm:
 - "2.0"
 - "2.1"
 - "2.2.2"
-- "2.3.1"
+- "2.3.7"
 - "2.4.0"
+- "2.5.0"
+- "2.6.0"
 - ruby-head
 - jruby-19mode
 - jruby-head
@@ -24,6 +26,8 @@ gemfile:
 - Gemfile.activerecord42
 - Gemfile.activerecord50
 - Gemfile.activerecord51
+- Gemfile.activerecord52
+- Gemfile.activerecord52_with_activesupport52
 
 matrix:
   allow_failures:
@@ -39,3 +43,12 @@ matrix:
       gemfile: Gemfile.activerecord51
     - rvm: "2.1"
       gemfile: Gemfile.activerecord51
+    - rvm: "2.0"
+      gemfile: Gemfile.activerecord52
+    - rvm: "2.1"
+      gemfile: Gemfile.activerecord52
+    - rvm: "2.0"
+      gemfile: Gemfile.activerecord52_with_activesupport52
+    - rvm: "2.1"
+      gemfile: Gemfile.activerecord52_with_activesupport52
+

Gemfile.activerecord52

@@ -0,0 +1,17 @@
+source 'https://rubygems.org'
+gemspec
+
+gem 'actionview', '~> 5.2.0'
+gem 'activerecord', '~> 5.2.0'
+
+platforms :jruby do
+  gem 'activerecord-jdbcsqlite3-adapter'
+  gem 'activerecord-jdbcmysql-adapter'
+  gem 'activerecord-jdbcpostgresql-adapter'
+end
+
+platforms :ruby do
+  gem 'sqlite3', '~> 1.3.6'
+  gem 'mysql2', '>= 0.3.18', '< 0.5'
+  gem 'pg', '~> 0.18'
+end

Gemfile.activerecord52_with_activesupport52

@@ -0,0 +1,18 @@
+source 'https://rubygems.org'
+gemspec
+
+gem 'actionview', '~> 5.2.0'
+gem 'activerecord', '~> 5.2.0'
+gem 'activesupport', '~> 5.2.0'
+
+platforms :jruby do
+  gem 'activerecord-jdbcsqlite3-adapter'
+  gem 'activerecord-jdbcmysql-adapter'
+  gem 'activerecord-jdbcpostgresql-adapter'
+end
+
+platforms :ruby do
+  gem 'sqlite3', '~> 1.3.6'
+  gem 'mysql2', '>= 0.3.18', '< 0.5'
+  gem 'pg', '~> 0.18'
+end