Merge pull request #11 from caiduoi/develop

Fix DB and Create, view, show, delete subject and task
Edit Subject
Merge pull request #10 from SonChee/develop

view course detail
Merge pull request #13 from caiduoi/develop

Edit Subject
View-Courses-Details
Merge pull request #14 from PhamPhi/develop

Details Courses
Delete-Courses
Merge pull request #16 from PhamPhi/develop

Delete-Courses
Admin: create, delete, list all supervisor
Merge pull request #15 from caiduoi/develop

Admin: create, delete, list all supervisor
Assign trainee to course