refs #9889, refs #8592
This commit removes support for twitter and linkedin profile pictures,
as they are too small.
Test plan:
* rake db:migrate
* go view some profile pages
* the profile pics should not be ghetto-scaled
Change-Id: Ibea84420351cabbb496b1a8e5860d6e5834bb8ac
Reviewed-on: https://gerrit.instructure.com/13030
Reviewed-by: Brian Palmer <brianp@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>