/*
  Given a list of intervals:
  example: [
    {7, 9},
    {2, 4},
    {1, 3},
    {3, 5},
    {2, 5},
    {4, 6}
  ]

  write a function that merges overlapping intervals.
  example output/return: [
    {7, 9},
    {1, 6}
  ]
*/

/*
  Interval => Span of time, with start and end
  the start time for a given interval is always less than or equal to the end time
  the start and end times are always positive integers

  |-------|
        |--------|
  |--------------|  -> overlap

  |-------|
          |------|
  |--------------|  -> overlap

  |-----|
          |------|
  |-----| |------|  -> no overlap
*/