To support IPv6

[Rhilip]

When I try to connect my mysql via an ipv6 address, It fails.
However the origin PyMySQL can do it after PyMySQL@b15c673 with
issues PyMySQL#118
Can you also fix it, and update the pypi?

And This is my temporary solution.

diff -Naur cymysql/connections.py cymysql-ipv6/connections.py
--- cymysql/connections.py    2017-06-10 03:51:56.000000000 -0400
+++ cymysql-ipv6/connections.py    2017-10-27 05:12:51.125249151 -0400
@@ -398,13 +398,14 @@
                 self.host_info = "Localhost via UNIX socket"
                 if DEBUG: print('connected using unix_socket')
             else:
-                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-                t = sock.gettimeout()
-                sock.settimeout(self.connect_timeout)
-                sock.connect((self.host, self.port))
+                sock = socket.create_connection((self.host, self.port), self.connect_timeout)
                 self.host_info = "socket %s:%d" % (self.host, self.port)
                 if DEBUG: print('connected using socket')
-            sock.settimeout(t)
         except socket.error as e:
             sock.close()
             raise OperationalError(2003, "Can't connect to MySQL server on %r (%s)" % (self.host, e.args[0]))

[nakagami]

thanks, I have modified and uploaded it