Adjust adapter gem versions to required versions in Rails

It was impossible to run tests on Travis CI due too lose requirements
on gem versions. Bundler was loading version too new for specific
Rails version.

Appraisals

@@ -1,28 +1,39 @@
 appraise "activerecord-3.2" do
   gem "activerecord", "~> 3.2.0"
-  gem "mysql", "~> 2.9.1"
-  gem "mysql2", "~> 0.3.11"
+  gem "mysql", "~> 2.8"
+  gem "mysql2", "~> 0.3.10"
+  gem 'pg', '~> 0.11'
+  gem "sqlite3", "~> 1.3.5"
 end
 
 appraise "activerecord-4.0" do
   gem "activerecord", "~> 4.0.0"
-  gem "mysql", "~> 2.9.1"
-  gem "mysql2", "~> 0.3.11"
+  gem "mysql", "~> 2.8"
+  gem "mysql2", "~> 0.3.10"
+  gem 'pg', '~> 0.11'
+  gem "sqlite3", "~> 1.3.6"
+
 end
 
 appraise "activerecord-4.2" do
   gem "activerecord", "~> 4.2.0"
-  gem "mysql", "~> 2.9.1"
-  gem "mysql2", "~> 0.3.11"
+  gem 'mysql', '~> 2.9'
+  gem 'mysql2', '>= 0.3.13', '< 0.5'
+  gem 'pg', '~> 0.15'
+  gem "sqlite3", "~> 1.3.6"
 end
 
 appraise "activerecord-5.0" do
   gem "activerecord", "~> 5.0.0"
   gem "mysql2", "~> 0.4.4"
+  gem "pg", ">= 0.18", "< 2.0"
+  gem "sqlite3", "~> 1.3.6"
 end
 
 appraise "activerecord-edge" do
   gem "arel", github: "rails/arel"
   gem "activerecord", github: "rails/rails"
   gem "mysql2", "~> 0.3.11"
+  gem "pg", ">= 0.18", "< 2.0"
+  gem "sqlite3", "~> 1.3.6"
 end

Gemfile

@@ -10,6 +10,4 @@ end
 group :test do
   gem 'rake', '~> 10.0'
   gem 'rspec', '~> 2.14.0'
-  gem 'pg', '>= 0.15.1'
-  gem 'sqlite3', '>= 1.3.7'
 end

gemfiles/activerecord_3.2.gemfile

@@ -3,8 +3,10 @@
 source "http://rubygems.org"
 
 gem "activerecord", "~> 3.2.0"
-gem "mysql", "~> 2.9.1"
-gem "mysql2", "~> 0.3.11"
+gem "mysql", "~> 2.8"
+gem "mysql2", "~> 0.3.10"
+gem "pg", "~> 0.11"
+gem "sqlite3", "~> 1.3.5"
 
 group :development do
   gem "appraisal"
@@ -14,8 +16,6 @@ end
 group :test do
   gem "rake", "~> 10.0"
   gem "rspec", "~> 2.14.0"
-  gem "pg", ">= 0.15.1"
-  gem "sqlite3", ">= 1.3.7"
 end
 
-gemspec :path => "../"
+gemspec path: "../"

gemfiles/activerecord_4.0.gemfile

@@ -3,8 +3,10 @@
 source "http://rubygems.org"
 
 gem "activerecord", "~> 4.0.0"
-gem "mysql", "~> 2.9.1"
-gem "mysql2", "~> 0.3.11"
+gem "mysql", "~> 2.8"
+gem "mysql2", "~> 0.3.10"
+gem "pg", "~> 0.11"
+gem "sqlite3", "~> 1.3.6"
 
 group :development do
   gem "appraisal"
@@ -14,8 +16,6 @@ end
 group :test do
   gem "rake", "~> 10.0"
   gem "rspec", "~> 2.14.0"
-  gem "pg", ">= 0.15.1"
-  gem "sqlite3", ">= 1.3.7"
 end
 
-gemspec :path => "../"
+gemspec path: "../"

gemfiles/activerecord_4.2.gemfile

@@ -3,8 +3,10 @@
 source "http://rubygems.org"
 
 gem "activerecord", "~> 4.2.0"
-gem "mysql", "~> 2.9.1"
-gem "mysql2", "~> 0.3.11"
+gem "mysql", "~> 2.9"
+gem "mysql2", ">= 0.3.13", "< 0.5"
+gem "pg", "~> 0.15"
+gem "sqlite3", "~> 1.3.6"
 
 group :development do
   gem "appraisal"
@@ -14,8 +16,6 @@ end
 group :test do
   gem "rake", "~> 10.0"
   gem "rspec", "~> 2.14.0"
-  gem "pg", ">= 0.15.1"
-  gem "sqlite3", ">= 1.3.7"
 end
 
-gemspec :path => "../"
+gemspec path: "../"

gemfiles/activerecord_5.0.gemfile

@@ -4,6 +4,8 @@ source "http://rubygems.org"
 
 gem "activerecord", "~> 5.0.0"
 gem "mysql2", "~> 0.4.4"
+gem "pg", ">= 0.18", "< 2.0"
+gem "sqlite3", "~> 1.3.6"
 
 group :development do
   gem "appraisal"
@@ -13,8 +15,6 @@ end
 group :test do
   gem "rake", "~> 10.0"
   gem "rspec", "~> 2.14.0"
-  gem "pg", ">= 0.15.1"
-  gem "sqlite3", ">= 1.3.7"
 end
 
-gemspec :path => "../"
+gemspec path: "../"

gemfiles/activerecord_5.1.gemfile

@@ -13,8 +13,8 @@ end
 group :test do
   gem "rake", "~> 10.0"
   gem "rspec", "~> 2.14.0"
-  gem "pg", ">= 0.15.1"
-  gem "sqlite3", ">= 1.3.7"
+  gem "pg", ">= 0.18", "< 2.0"
+  gem "sqlite3", "~> 1.3.6"
 end
 
 gemspec :path => "../"

gemfiles/activerecord_edge.gemfile

@@ -2,9 +2,11 @@
 
 source "http://rubygems.org"
 
-gem "arel", :github => "rails/arel"
-gem "activerecord", :github => "rails/rails"
+gem "arel", github: "rails/arel"
+gem "activerecord", github: "rails/rails"
 gem "mysql2", "~> 0.3.11"
+gem "pg", ">= 0.18", "< 2.0"
+gem "sqlite3", "~> 1.3.6"
 
 group :development do
   gem "appraisal"
@@ -14,8 +16,6 @@ end
 group :test do
   gem "rake", "~> 10.0"
   gem "rspec", "~> 2.14.0"
-  gem "pg", ">= 0.15.1"
-  gem "sqlite3", ">= 1.3.7"
 end
 
-gemspec :path => "../"
+gemspec path: "../"