Merge pull request #22 from DivineOmega/fix/add-activity-due-date

Fix undefined `$due_date` variable in `ActivitiesController` `addAnActivity` method

Author: mykhailo-riabokon

src/Controllers/ActivitiesController.php

@@ -226,7 +226,7 @@ public function addAnActivity(
             'subject'      => $this->val($options, 'subject'),
             'type'         => $this->val($options, 'type'),
             'done'       => APIHelper::prepareFormFields($this->val($options, 'done')),
-            'due_date'   => DateTimeHelper::toSimpleDate($due_date),
+            'due_date'   => DateTimeHelper::toSimpleDate($this->val($options,'dueDate')),
             'due_time'     => $this->val($options, 'dueTime'),
             'duration'     => $this->val($options, 'duration'),
             'user_id'      => $this->val($options, 'userId'),