add audit trail

lib/submission_events.rb

@@ -3,6 +3,17 @@
 module SubmissionEvents
   TRACKING_PARAM_LENGTH = 6
 
+  EVENT_NAMES = {
+    send_email: 'Email sent',
+    send_sms: 'SMS sent',
+    open_email: 'Email opened',
+    click_email: 'Email link clicked',
+    click_sms: 'SMS link clicked',
+    start_form: 'Submission started',
+    view_form: 'Form viewed',
+    complete_form: 'Submission completed'
+  }.freeze
+
   module_function
 
   def build_tracking_param(submitter, event_type = 'click_email')