Merge branch 'release/3.1.1_alpha3' into develop
重命名一些方法
使用PromiseKit
修改一处崩溃
注释掉无用的代码
可选择测试模式
Merge branch 'feature/exam_improvement' into develop
修改一些图片
修改熟悉度计算
Merge branch 'release/3.1.1_alpha4'
modify read
Merge branch 'hotfix/readme_modification'