use jdbc for activerecord if running under jruby

examples/lib/activerecord.rb

@@ -1,6 +1,6 @@
-require 'activerecord'
+require 'active_record'
 
-ActiveRecord::Base.establish_connection(:adapter => "sqlite3", :dbfile => ":memory:")
+ActiveRecord::Base.establish_connection(:adapter => "#{"jdbc" if defined?(JRUBY_VERSION)}sqlite3", :database => ":memory:")
 
 ActiveRecord::Schema.define(:version => 1) do
   create_table :widgets do |t|

features/step_definitions/database_cleaner_steps.rb

@@ -11,7 +11,7 @@ When "I run my scenarios that rely on a clean database" do
   Dir.chdir(full_dir) do
     ENV['ORM'] = @orm.downcase
     ENV['STRATEGY'] = @strategy
-    @out = `cucumber features`
+    @out = `#{"jruby -S " if defined?(JRUBY_VERSION)}cucumber features`
     @status = $?.exitstatus
   end
 end