Fix deleting files

tests/main.cpp

+#define CATCH_CONFIG_MAIN
+#include "catch.hpp"

tests/tree_node.cpp

+#include <catch.hpp>
+#include "tree_node.hpp"
+#include <string>
+
+TEST_CASE(){
+  TreeNode node;
+  string goal = "Get Password";
+  node.set_goal(goal);
+  REQUIRE(node.get_goal() == goal);
+}