[Gsoc-mentors-2019] Final submissions are due soon

Hi mentors,

The final submissions are due in less than 24 hours, so we're getting a lot of submissions now with people finalizing their draft proposal, or rushing to submit anything. I'm cutting back with feedback to students, since 1) they waited until the last minute and 2) they likely won't have time to fix any issues anyway. After the deadline, I'll go through and hide the ones that clearly don't belong, and we can begin discussions from there. We've got several strong candidates this year.