Item collision event

[terox]

Issue Number

#523

Overview of PR

We added the functionality to detect collision between items in the same group.

Now you can detect collisions doing:

export default function Timetable() {
  const handleItemCollision = (currentItem, item) => {
    console.log('Item ' + currentItem.id + 'collided with ' + item.id)
  }

  return (
    <Timeline onCollision={this.handleItemCollision} />
  );
}

Authors of commit @GabrielCrackPro @albertoncp @terox