perform ICMP pings on posix systems

speedtest_cli.py

@@ -316,8 +316,13 @@ def getBestServer(servers):
 
     results = {}
     for server in servers:
-        cum = 0
         url = os.path.dirname(server['url'])
+        if os.name == 'posix':
+            cmd = 'ping -c 3 ' + url.split('/')[2] + ' | tail -n 1'
+            pingoutput = os.popen(cmd).read()
+            avg = pingoutput.split('/')[4]
+        else:
+            cum = 0
             for i in range(0, 3):
                 uh = urlopen('%s/latency.txt' % url)
                 start = time.time()