Make all of the examples py3 syntax friendly (#816)

diff --git a/examples/sni/client.py b/examples/sni/client.py
index 428525b..d4a751f 100644
--- a/examples/sni/client.py
+++ b/examples/sni/client.py
@@ -1,6 +1,8 @@
 # Copyright (C) Jean-Paul Calderone
 # See LICENSE for details.
 
+from __future__ import print_function
+
 from sys import argv, stdout
 from socket import socket
 
@@ -13,21 +15,21 @@
     by argv[1], of it.
     """
     if len(argv) < 2:
-        print 'Usage: %s <hostname>' % (argv[0],)
+        print('Usage: %s <hostname>' % (argv[0],))
         return 1
 
     client = socket()
 
-    print 'Connecting...',
+    print('Connecting...', end="")
     stdout.flush()
     client.connect(('127.0.0.1', 8443))
-    print 'connected', client.getpeername()
+    print('connected', client.getpeername())
 
     client_ssl = Connection(Context(TLSv1_METHOD), client)
     client_ssl.set_connect_state()
     client_ssl.set_tlsext_host_name(argv[1])
     client_ssl.do_handshake()
-    print 'Server subject is', client_ssl.get_peer_certificate().get_subject()
+    print('Server subject is', client_ssl.get_peer_certificate().get_subject())
     client_ssl.close()
 
 
diff --git a/examples/sni/server.py b/examples/sni/server.py
index e0c159a..891c6c5 100644
--- a/examples/sni/server.py
+++ b/examples/sni/server.py
@@ -1,6 +1,8 @@
 # Copyright (C) Jean-Paul Calderone
 # See LICENSE for details.
 
+from __future__ import print_function
+
 from sys import stdout
 from socket import SOL_SOCKET, SO_REUSEADDR, socket
 
@@ -29,10 +31,10 @@
     port.bind(('', 8443))
     port.listen(3)
 
-    print 'Accepting...',
+    print('Accepting...', end="")
     stdout.flush()
     server, addr = port.accept()
-    print 'accepted', addr
+    print('accepted', addr)
 
     server_context = Context(TLSv1_METHOD)
     server_context.set_tlsext_servername_callback(pick_certificate)