Insert a random incident into a collection
@param {Array} types - the types of incidents ['info', 'success']
@param {Date} start - the start Date
@param {Date} end - the end Date
@return None
function randomIncident(types, start, end) {
  const x1 = randomDate(start, end);
  const x2 = new Date(x1);
  x2.setDate(x1.getDate() + (Math.floor(Math.random() * 45)));
  Incidents.insert({
    x1: x1.getTime(),
    x2: x2.getTime(),
    y1: (Math.floor(Math.random() * 99)),
    type: types[(Math.floor(Math.random() * 2))],
  });
}