Merge pull request #106 from p-l-/fix-101

python --version may output to stderr (fixes #101)

run_scapy

 #! /bin/sh
 DIR=$(dirname $0)
-if python --version | grep -q '^Python 2'; then
+if python --version 2>&1 | grep -q '^Python 2'; then
     PYTHON=python
 else
     PYTHON=python2

test/run_tests

 #! /bin/bash
 DIR=$(dirname $0)/..
-if python --version | grep -q '^Python 2'; then
+if python --version 2>&1 | grep -q '^Python 2'; then
     PYTHON=python
 else
     PYTHON=python2