Given a list of instructors and courses they are teaching, returns the list of instructors teaching a given course.

Organize Instructors

const organizeInstructors = function(instructors) {
  let orgIns = new Object();
  for (let i in instructors){
    if (orgIns.hasOwnProperty(instructors[i].course)){
      orgIns[instructors[i].course].push(instructors[i].name);
    }else {
      orgIns[instructors[i].course] = [instructors[i].name];
    }
  }
  return orgIns;
};