remove unnecessary python3 imports

we are using python3, these imports are no longer necessary. in order to
remove the `future` library, we might as well remove these dependencies
(even if it works with them)

Author: mazunki

vmrunner/boot.py

@@ -3,8 +3,6 @@
 
 # pylint: disable=invalid-name
 
-from __future__ import print_function
-
 import os
 import sys
 import argparse

vmrunner/prettify.py

@@ -3,7 +3,6 @@
 
 # pylint: disable=invalid-name,line-too-long
 
-from __future__ import print_function
 from builtins import str
 from builtins import range
 

vmrunner/validate_vm.py

@@ -3,8 +3,6 @@
 
 # pylint: disable=invalid-name
 
-from __future__ import print_function
-
 import json
 import sys
 import os

vmrunner/vmrunner.py

@@ -5,10 +5,6 @@
 
 # pylint: disable=line-too-long, too-many-lines, invalid-name, fixme, broad-exception-raised, broad-exception-caught, too-many-arguments, too-many-branches, too-many-statements, too-many-instance-attributes, too-many-locals
 
-from __future__ import print_function
-from __future__ import absolute_import
-
-
 from builtins import hex
 from builtins import chr
 from builtins import str