Update install-deps

[chakpongchung]

for 18.04 LTS

[cameronnapoli]

Reproduced error on Ubuntu 18.04.1 LTS
line sudo apt-get install -y python-software-properties fails.
Error:
E: Package 'python-software-properties' has no installation candidate

[cameronnapoli]

@chakpongchung Instead of replacing line 178: sudo apt-get install -y python-software-properties, you probably need to an if statement for that checking if the Ubuntu version is 18 or not.