Fix 067_Add_Binary for Python 3 (#35)

* Fix 067_Add_Binary.py for Python, @yuchenliu15

Author: yuchenliu15

python/067_Add_Binary.py

@@ -53,7 +53,7 @@ def addBinary(self, a, b):
             if (lsb + pos) >= 0:
                 curr += int(b[pos])
             res = str(curr % 2) + res
-            curr /= 2
+            curr //= 2
             pos -= 1
         if curr == 1:
             res = '1' + res