tools: Use __future__.absolute_import to fix time bugs

willie/tools/__init__.py

@@ -17,6 +17,7 @@
 from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals
+from __future__ import absolute_import
 
 import sys
 import os

willie/tools/calculation.py

@@ -1,6 +1,7 @@
 # coding=utf8
 """Tools to help safely do calculations from user input"""
 from __future__ import unicode_literals
+from __future__ import absolute_import
 
 import time
 import numbers

willie/tools/time.py

@@ -1,6 +1,7 @@
 # coding=utf8
 """Tools for getting and displaying the time."""
 from __future__ import unicode_literals
+from __future__ import absolute_import
 
 import datetime
 try: