How to solve add-apt-repository command not found error on Ubuntu 16.04
To solve the add-apt-repository command not found error the first thing we need to do is to download the following packages.
sudo apt-get install python-software-properties software-properties-common
When done installing, copy the next command
sudo apt-get install apt-file
Now we need to update apt-file. This will take sometime to update. I suggest that you grab a coffee while at it.
sudo apt-file update
After it has been updated you can add the repository using add-apt-repository command.