add (failing) big_serial schema dump test from Rails 4.2

Author: kares

test/db/postgresql/uuid_test.rb

@@ -55,3 +55,24 @@ def test_auto_create_uuid
   end
 
 end if Test::Unit::TestCase.ar_version('4.0')
+
+class PostgresqlLargeKeysTest < Test::Unit::TestCase # ActiveRecord::TestCase
+
+  def setup
+    connection.create_table('big_serials', :id => :bigserial) do |t|
+      t.string 'name'
+    end
+  end
+
+  def test_omg
+    schema = StringIO.new
+    ActiveRecord::SchemaDumper.dump(connection, schema)
+    assert_match "create_table \"big_serials\", id: :bigserial, force: :cascade",
+      schema.string
+  end
+
+  def teardown
+    connection.drop_table "big_serials"
+  end
+
+end if Test::Unit::TestCase.ar_version('4.2')