merge list-quiz page
fix bug in index.html.erb
fix conflict when merge
fix index
fix index
Merge remote-tracking branch 'upstream/master'

Conflicts:
	app/views/quizzes/index.html.erb
fix header in quiz-list page
Merge branch 'master' of https://github.com/trangnt57/socio_quiz into trangnt57-master

Conflicts:
	app/views/quizzes/index.html.erb
Update to lasted core feature.
Merge branch 'trangnt57-master'