Remove print statements.

I was originally going to switch to print function, but frankly I can't
see any reason to keep these.  I don't know what data it's leaking into
the logs, but it certainly doesn't seem useful

StringIO is not in Py3.  And it's not used at all, so removing that
import.  Seems to work with Py3 now.  More testing is required.

symposion/reviews/views.py

@@ -1,6 +1,5 @@
 import csv
 import random
-import StringIO
 
 from django.contrib.auth.decorators import login_required
 from django.core.mail import send_mass_mail
@@ -291,8 +290,6 @@ def review_admin(request, section_slug):
                     user=user,
                     proposal__kind__section__slug=section_slug,
                 )
-                print section_slug
-                print [vote.proposal.kind.section.slug for vote in user_votes]
                 user.total_votes = user_votes.exclude(
                     vote=LatestVote.VOTES.ABSTAIN,
                 ).count()