Install VS CODE on ubuntu 18.04 LTS

ref: https://qiita.com/shaching/items/69dfc000f13ff55dde99

to summarize:

1. download *.deb from official site, for me it's "code_1.26.1-1534444688_amd64.deb"
2. sudo apt install libgconf-2-4
3. sudo apt --fix-broken install
4. sudo dpkg -i code_1.26.1-1534444688_amd64.deb