Cannot connect to Ipv6.

Hi,

I am trying to connect to ipv6 address using this library. But while trying to connect to an Ipv6 server it raise an error: `gaierror(-9, 'Address family for hostname not supported')`

Start by reproducing the connection attempt against an IPv6 server and trace the library's hostname resolution and socket-connection entry point. The issue names no files or tests, so locate the relevant connection code and add coverage for an IPv6 address; done means the connection no longer raises gaierror(-9).

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