Ubuntu14.04 升级到16.04

sudo apt update
sudo apt dist-upgrade 

make sure the version is now Ubuntu 14.04.4. 

cat /etc/lsb-release

and start Ubuntu 16.04 installation with

sudo do-release-upgrade -d

如果遇到下面的错误：
The required dependency 'apt (>= 1.0.1ubuntu2.13)' is not installed.
这样解决：


	To upgrade your version of apt from a terminal window, type in the following:

sudo apt-get download apt 

	if the above doesn't work, you can also download it with wget by running the following line:

wget http://security.ubuntu.com/ubuntu/pool/main/a/apt/apt_1.0.1ubuntu2.13_amd64.deb 

	then type in 

sudo dpkg -i apt*.deb