Prepares binary search tree data structure.
First test passes
Add method added. Also adds convenience method has_child in node class
some small changes
Implement max, that finx the highest node value of a tree
Implement min, that find the lowest node value of a tree
Adds is_search_node that checks whether a node is possibly part of a binary search tree
First is_search_tree attempt. Valid case seems to pass. Let s try the negation
is_search_tree implemented