Update FetchActivity

[poroia]

What feature would you like implemented/changed
return all the prerequisites activities for a particular activity
for now, just make the prerequisite activity the previous activity

Type of Request
GET

Route Url
/activities/{{activity_id}}

Data Returned

{
  "prerequisite_activities": [
    {
      "id": 69
    },
    {
      "id": 420
    }
  ]
}

Create/Update Postman/Documentation
FetchActivity