Adding SSL support with official OpenResty SSL cosockets implementation

Adding support for SSL:
- wss:// scheme should be used for SSL connections
- ssl_verify parameter can be passed along with options table to connect method (false by default)
Ugh, test 24 is defined with ssl_verify = true, not sure what I'm missing.
Maybe handshake fails because you're not using the patched version of test-nginx that adds udp_reply? Not sure if that got merged, but as far as I remember it was needed for the host name verification.