insert office in the list of valid supervisors

sails/src/api/models/Student.js

@@ -339,7 +339,7 @@ module.exports = {
     })
     .spread((sups, me) => {
       // The requester is an office, so it has to be appended to the list of valid supervisors
-      sups.append(me);
+      sups.push(me);
       return callback(null, sups);
     })
     .catch((err) => {