Port process

src/python/pants/process/BUILD

@@ -3,6 +3,7 @@
 
 python_library(
   dependencies = [
+    '3rdparty/python:future',
     '3rdparty/python:fasteners',
     '3rdparty/python:psutil',
     'src/python/pants/util:dirutil',

src/python/pants/process/xargs.py

@@ -5,6 +5,7 @@
 from __future__ import absolute_import, division, print_function, unicode_literals
 
 import errno
+from builtins import object
 
 from pants.util.process_handler import subprocess
 

tests/python/pants_test/process/BUILD

@@ -3,6 +3,7 @@
 
 python_tests(
   dependencies = [
+    '3rdparty/python:future',
     '3rdparty/python:mock',
     '3rdparty/python:six',
     'src/python/pants/process',

tests/python/pants_test/process/test_lock.py

@@ -8,6 +8,7 @@
 import shutil
 import tempfile
 import unittest
+from builtins import str
 from multiprocessing import Manager, Process
 from threading import Thread