刚装完1.0.3两天，1.0.4发布了，乘项目还没有开始，赶快升级。升级过程
1.设置环境变量：
RAILS_ENV=production
export RAILS_ENV
2. 获取最新代码：
cd redmine-2.3/plugins/redmine_backlogs
git fetch --tags origin
git tag
3. checkout到最新的tag v1.0.4
git checkout v1.0.4
4. 回到redmine-2.3目录，运行安装命令：
bundle exec rake redmine:backlogs:install
2.3.2.stable.12037. You are running backlogs v1.0.4, latest version is 1.0.4 =====================================================
Redmine Backlogs Installer
=====================================================
Installing to the production environment.
Fetching card labels from http://git.gnome.org...done!
Story and task trackers are now set.
Migrating the database...** Invoke redmine:plugins:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute redmine:plugins:migrate
** Invoke db:schema:dump (first_time)
** Invoke environment
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:schema:dump
** Invoke redmine:backlogs:fix_positions (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute redmine:backlogs:fix_positions
done!
5. 重新启动 redmine。升级成功。