capture resetswift output in probetests

This change makes the dots prettier during probetests

When calling the resetswift script, the probetests will use subprocess
to redirect stderr to stdout and capture stdout into a buffer.  We print
the captured buffer from resetswift's combined stdout/stderr and let
nosetests stdout capturing handle printing the output for debug only if a
test fails.

Change-Id: I022512f2ef5a4c43b0e49264bad1bca98c1f0299

test/probe/common.py

@@ -16,7 +16,7 @@
 from httplib import HTTPConnection
 from os import kill
 from signal import SIGTERM
-from subprocess import call, Popen
+from subprocess import Popen, PIPE, STDOUT
 from time import sleep, time
 
 from swiftclient import get_auth, head_account
@@ -122,7 +122,9 @@ def kill_nonprimary_server(primary_nodes, port2server, pids):
 
 
 def reset_environment():
-    call(['resetswift'])
+    p = Popen("resetswift 2>&1", shell=True, stdout=PIPE)
+    stdout, _stderr = p.communicate()
+    print stdout
     pids = {}
     try:
         port2server = {}