Only execute the JsonVersion tests against ActiveRecord4 since there is no ActiveRecord3 support for it

spec/models/json_version_spec.rb

@@ -1,11 +1,12 @@
-require 'rails_helper'
+if JsonVersion.table_exists?
 
-describe JsonVersion, :type => :model do
-  it "should include the `VersionConcern` module to get base functionality" do
-    expect(JsonVersion).to include(PaperTrail::VersionConcern)
-  end
+  require 'rails_helper'
+
+  describe JsonVersion, :type => :model do
+    it "should include the `VersionConcern` module to get base functionality" do
+      expect(JsonVersion).to include(PaperTrail::VersionConcern)
+    end
 
-  if ENV['DB'] == 'postgres' || JsonVersion.table_exists?
     describe "Methods" do
       describe "Class" do
 
@@ -71,8 +72,9 @@ describe JsonVersion, :type => :model do
             end
           end
         end
-
       end
+
     end
   end
+
 end

test/dummy/db/migrate/20110208155312_set_up_test_tables.rb

@@ -60,7 +60,7 @@ class SetUpTestTables < ActiveRecord::Migration
     end
     add_index :post_versions, [:item_type, :item_id]
 
-    if ENV['DB'] == 'postgres'
+    if ENV['DB'] == 'postgres' && ::ActiveRecord::VERSION::MAJOR >= 4
       create_table :json_versions, :force => true do |t|
         t.string   :item_type, :null => false
         t.integer  :item_id,   :null => false