fix for crash on no additional facilitators

lib/sessions.js

@@ -46,8 +46,11 @@ function sessionFaclitiators( session ) {
   });
 
   // separate out remaining facilitators (if any)
-  var additional = session.facilitators.split( '\n' );
+  var additional = session.facilitators;
-  additional.forEach( function( facilitator ) {
+  if( !additional ) {
+    return facilitators;
+  }
+  additional.split( '\n' ).forEach( function( facilitator ) {
     var twitterRegExp = /\B@[a-z0-9_-]+/ig; // matches a twitter handle
 
     // look for their twitter handle and separate that out from their name