Use print() function in both Python 2 and Python 3

Signed-off-by: cclauss <cclauss@me.com>

hack/prow/run_tests.py

@@ -20,6 +20,7 @@
    https://k8s-testgrid.appspot.com
 """
 
+from __future__ import print_function
 import os, sys, json, re, argparse, calendar, time, subprocess, shlex
 
 def get_classname(test_script):
@@ -86,8 +87,8 @@ def upload_results(outdir, test_script, buildnum, bucket):
   classname = get_classname(test_script)
   args = shlex.split("gsutil cp -R gcs_out/ gs://%s/logs/%s/%s" % (bucket, classname, buildnum))
   p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-  for line in p.stdout:
-    print line
+  for line in str(p.stdout):
+    print(line)
 
 def run_tests(test_script, log_path, exit_status, started, finished, test_results):
   """ execute the test script, grab the start time, finish time, build logs and exit status
@@ -109,9 +110,9 @@ def run_tests(test_script, log_path, exit_status, started, finished, test_result
   classname = get_classname(test_script)
   build_log_file = open(log_path, 'w')
   p = subprocess.Popen(['bash','-x',test_script], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-  for line in p.stdout:
+  for line in str(p.stdout):
     build_log_file.write(line)
-    print line.rstrip()
+    print(line.rstrip())
     if '--- PASS' in line:
       match = re.match('.*--- PASS: ([^ ]+) \(([0-9.]+)s\)', line)
       (name, seconds) = match.group(1, 2)