Faster DNS

用ping實測新的DNS，1.1.1.1比Google快一倍！

Google DNS (8.8.8.8 and 8.8.4.4) has been very useful but sometimes still not quick. CloudFlare provides public DNS (1.1.1.1 and 1.0.0.1) claiming faster than Google. Just tested by ping, 1.1.1.1 has shorter than 15ms delay while 8.8.8.8 takes longer than 25ms. So it's time to make a change!