Using the code from chapter 10 (https://github.com/ccnycs/csc212/tree/master/code/chap10)

Implement:

1. the bt_class.template
2. A function that checks if the binary tree is a binary search tree:

bool isBST()

3. A function that checks if the binary tree is a max or min heap:

bool isHeap(std::string htype)

called with either isHeap('min') or isHeap('max')

these functions can either be completed as part of the bt_class or as standalone functions. If the latter, the signature can be modifed to accept the root node of the binary tree.