Submitting on behalf of students #216
Description
Especially when the system/users are failing (which has been a little often lately, especially until we actually support grace days), we often get students submitting their pset by email, usually at the very last minute of the deadline. Instead of giving them an extension, having them upload, and then confirming that they actually submitted the same file as email, it would be way easier to support the following feature request:
Allow staff to upload psets on behalf of a specified student.
Server: https://alg.csail.mit.edu
Referer: https://alg.csail.mit.edu/6.006
Rails: 5.0.0.1
Ruby: ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]