fix long titles in assignments_2 student view
fix long titles in assignments_2 student view

fixes COMMS-1836

Test Plan:
- create an assignment with a really long title
- as a student view that assignment
- notice no horizontal scroll bar

Change-Id: Iaa3e958ddd70c12dbc15fb97511b778f6d6e44ca
Reviewed-on: https://gerrit.instructure.com/178095
Tested-by: Jenkins
Reviewed-by: Landon Gilbert-Bland <60d9ff23682c863d36b48b4c32c5ce5f434d29c0@instructure.com>
QA-Review: Landon Gilbert-Bland <60d9ff23682c863d36b48b4c32c5ce5f434d29c0@instructure.com>
Product-Review: Steven Burnett <a0b450117c5d20a22d5c4d52bb8ae13adee003d8@instructure.com>

instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,sfu/canvas-lms