Add .social parser

[majormoses]

Add it, discovered here: sensu-plugins/sensu-plugins-network-checks#61

[weppos]

Thanks @mpchadwick. I'm going to close this issue as there are several parsers missing, and it creating a ticket with a request for each of them is going to create a lot of noise in the issue tracker.

Feel free to provide a PR and I'll happily review it.