Added binary search tree challenge.

graphs_trees/bst/test_bst.py

@@ -0,0 +1,37 @@
+from __future__ import print_function
+from nose.tools import assert_equal
+
+
+class TestTree(object):
+
+    def test_tree(self):
+        root = Node(5)
+        root.insert(2)
+        root.insert(8)
+        root.insert(1)
+        root.insert(3)
+
+        with captured_output() as (out, err):
+            root.in_order_traversal(sys.stdout.write)
+            assert_equal(out.getvalue().strip(), '12358')
+
+        root = Node(1)
+        root.insert(2)
+        root.insert(3)
+        root.insert(4)
+        root.insert(5)
+
+        with captured_output() as (out, err):
+            root.in_order_traversal(sys.stdout.write)
+            assert_equal(out.getvalue().strip(), '12345')
+
+        print('Success: test_tree')
+
+
+def main():
+    test = TestTree()
+    test.test_tree()
+
+
+if __name__ == '__main__':
+    main()