Add basic SNI support

By adding the server name as part of the TLS client configuration, gor
will now support connecting to hosts that require SNI (such as Amazon
API Gateway).

http_client.go

@@ -89,7 +89,7 @@ func (c *HTTPClient) Connect() (err error) {
 	}
 
 	if c.scheme == "https" {
-		tlsConn := tls.Client(c.conn, &tls.Config{InsecureSkipVerify: true})
+		tlsConn := tls.Client(c.conn, &tls.Config{InsecureSkipVerify: true, ServerName: c.host})
 
 		if err = tlsConn.Handshake(); err != nil {
 			return