ubuntu-16.04(Xenial Xerus) -> ubuntu-18.04(Bionic Beaver)
ubuntu 16.04_LTS(Xenial Xerus) --> ubuntu 18.04_LTS(Bionic Beaver) #> apt-get update && apt upgrade #> reboot #> uname -a Linux ubuntu 4.15.0-47-generic #50-Ubuntu SMP Wed Mar 13 10:44:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
2019.04.04