subject list contain list of visits

Two major changes:

• list of subjects contain condensed information about subject visits (dates and "status" of the visit, DONE, IN PROGRESS, UPCOMING, etc.)
• list of subjects can be customized to present only relevant columns Closes #140 (closed)

smash/web/api_views/appointment.py

 import logging
-import traceback
 from datetime import datetime
 
 from django.contrib.auth.decorators import login_required
@@ -87,7 +86,7 @@ def serialize_appointment(appointment):
     subject_string = ""
     nd_number = screening_number = phone_numbers = appointment_types = None
     if appointment.visit is not None:
-        title = appointment.visit.follow_up_title()
+        title = "Visit " + str(appointment.visit.visit_number)
         subject = appointment.visit.subject
         subject_string = subject.last_name + " " + subject.first_name
         nd_number = subject.nd_number