reorganize heap

Author: danghai

algorithms/heap/__init__.py

@@ -0,0 +1,3 @@
+from .binary_heap import *
+from .skyline import *
+from .sliding_window_max import *

heap/binary_heap.py renamed to algorithms/heap/binary_heap.py

@@ -1,6 +1,8 @@
-from heap.binary_heap import BinaryHeap
-from heap.skyline import get_skyline
-from heap.sliding_window_max import max_sliding_window
+from algorithms.heap import (
+    BinaryHeap,
+    get_skyline,
+    max_sliding_window
+)
 
 import unittest