Chached quiz view when Quiz closing time comes

Problem/Motivation

When the closing date of a quiz arrives, the Start Quiz button is not hidden from visitors until the site cache is cleared.

Steps to reproduce

• Create a quiz with closing time X
• Wait to time X + 1 minute (quiz should be close)
• Visit quiz page with a non administer user
• The start quiz button will be visible until you clear the cache.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes