How to remove every tace of mysql from Mac

Hello,

I'm trying to perform a clean install of mysql on my Mac Yosemite. I already had it installed, so as I read around I want to remove it completely. Reading in different articles and questions I followed a list of steps and then proceeded to the install process through homebrew. At the end I received a warning telling me that there was another mysql version at the location

/usr/local/opt/mysql/

I couldn't find it mentioned in any place, and it is a bit annoying because I'm wondering whether I'm missing something in some other place.

How can I find all the locations in which is installed mysql?