Nicer Question Admin Menu

Signed-off-by: René Meye <rene@meye.md>
No Mathjax in overview Table. Fixes #32

Signed-off-by: René Meye <rene@meye.md>
Updated Active_admin to 0.6.0 and original repo

Signed-off-by: René Meye <rene@meye.md>