checkForCollinearPoints = (p1, p2, p3) => (
  (p1.y - p2.y) * (p1.x - p3.x) ===
  (p1.y - p3.y) * (p1.x - p2.x)
)
checkForCollinearPoints
Figure out if the midpoint fits perfectly on a line between the two others.

@param {Object} p1 - Our initial point
@param {Number} p1.x - The x value of our initial point
@param {Number} p1.y - The y value of our initial point
@param {Object} p2 - Our mid-point
@param {Number} p2.x - The x value of our mid-point
@param {Number} p2.y - The y value of our mid-point
@param {Object} p3 - Our final point
@param {Number} p3.x - The x value of our final point
@param {Number} p3.y - The y value of our final point
@returns {Boolean} whether or not p2 sits on the line between p1 and p3.