我在Github上克隆一个项目，然后运行rake db:migrate，我收到此错误（项目名称为mini_fb_demo）：
$ git clone http://github.com/appoxy/mini_fb_demo.git
Initialized empty Git repository in /Users/ben/rails_projects/mini_fb_demo/.git/
remote: Counting objects: 102, done.
remote: Compressing objects: 100% (91/91), done.
remote: Total 102 (delta 24), reused 0 (delta 0)
Receiving objects: 100% (102/102), 77.94 KiB | 47 KiB/s, done.
Resolving deltas: 100% (24/24), done.
$ cd mini_fb_demo/
$ ls
README.markdown Rakefile app config db doc public script test
$ rake db:migrate
(in /Users/ben/rails_projects/mini_fb_demo)
rake aborted!
No such file or directory - /Users/ben/.minifb-demo-config.yml
造成这种情况的原因是什么？我感谢您的阅读。