change super() to super(Connection, self) for python2 and 3

[mxins]

change super() to super(Connection, self), super() does not work in python2

[mxins]

pyhive/trino.py line 51:
class Connection(PrestoConnection):
def init(self, *args, **kwargs):
super(Connection, self).init(*args, **kwargs):

[byungnam]

py2 code need this.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

meixinsheng seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}