add test file for future builtin functions

test/tests/builtins_future.py

+from future_builtins import hex, oct, map, zip, filter
+from itertools import imap, izip, ifilter
+
+value_list1 = [0, 42, 42L, -42, -42L, "", (), {}, []]
+value_list2 = [0, 100, 100L, -100, -100L]
+
+for value1 in value_list1:
+    try:
+        print(hex(value1))
+    except Exception as e:
+        print(type(e), e.message)
+
+for value2 in value_list2:
+    try:
+        print(oct(value2))
+    except Exception as e:
+        print(type(e), e.message)
+
+print(map == imap)
+print(zip == izip)
+print(filter == ifilter)