This tiny script will fetch and install the latest version of Hugo in Ubuntu.

upgrade-hugo.sh

#! /bin/bash
wget https://github.com`wget -qO- https://github.com/gohugoio/hugo/releases/latest | grep -oE -m 1 '/gohugoio/hugo/releases/download/v[0-9].[0-9][0-9].[0-9]/hugo_extended_[0-9].[0-9][0-9].[0-9]_Linux-64bit.deb'`
tar -xzf hugo*.tar.gz
sudo dpkg -i hugo*.deb && rm hugo*.deb;