test plan:
1. use canvas in any supported browser (including mobile)
2. you should not see a warning
3. use canvas in an unsupported browser (e.g. ie8, old firefox)
4. you should see an orangish warning at the top of every page
5. it should not be dismissable
Change-Id: I092455c416a754d102ddadbda99280856b4082de
Reviewed-on: https://gerrit.instructure.com/18524
QA-Review: Jon Jensen <jon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Joe Tanner <joe@instructure.com>
Jon Jensen