Binary Tree Maximum Path Sum
Given a binary tree, find the maximum path sum.
The path may start and end at any node in the tree.
Given the below binary tree:
Create a method to return the max sum of a single chain that is up to this node, so it is either the value of this node
max(left + right) + node.val.
The overall max sum is either the value of this single node
node.val or the sum of the max left and max right and the current node value
maxPath(node.left) + maxPath(node.right) + node.val.