Make the student attendance dashboard responsive

[mcflyhalf]

Edit the student attendance dashboard css so that it is responsive and works on smaller screens. Currently, on a smaller screen, the right half simply disappears. It should be pretty easy to make a simple media query that drops it below the left half on smaller screens.

[mcflyhalf]

Probably implemented in the far future as at the moment, we do not expect students to log in to the app making this a page that is never visited on the site. In future, it may make sense to have students able to log in to check their own attendance. But with the current features, there is so little interaction that the students can have with the site that it doesnt make sense to enable them as users.

This may change in future when the project becomes more mature