Merge pull request #544 from algo31031/rails_4.1.1

updated to  Rails 4.1.1 and ruby 2.1.2
Merge pull request #545 from algo31031/rails_4.1.1

Rails 4.1.1
Merge pull request #546 from algo31031/rails_4.1.1

course purchase bug fix
Merge pull request #548 from algo31031/rails_4.1.1

用户注册/编辑/登录的一点重构
this is what I have on my vps
one avatar to rule them all #550
Fixed #553, rails bug with jsonp
Merge pull request #555 from qichunren/master

Fixed #553, rails bug with jsonp