Using brew's qt and python3 formulae
Bonus: I have also added a script that embeds python into bundle, recursively adding dependencies from inside /usr/local/opt. That means that /usr/local/lib folders are not going to be copied. I saw one dependency to /usr/local/lib/gcc from one of numpy's modules, instead of pointing towards /usr/local/opt/gcc/lib/gcc.
Side effects: Renaming Qt5Custom to Qt5Brew