How to uninstall Qt Creator on Mac Yosemite
I figured it out. Basically I was not able to locate the file because it never shows up in finder but here is how to get there.
From 'Go' menu on Finder, select 'Go to Folder'
Type ~/Library
This will take you to file system. I had two folders related to Qt (Qt and Qt 5.1). Both folders had MaintenanceTool file in it which I run and it asks if you want to uninstall and select yes. This will uninstall Qt Creator and all its components.
Update
Like aksiksi noted in comment below, it maybe installed in root folder for new versions. To go there type /
in 'Go to Folder' dialog and look for Qt installation there.
Remove the main Qt directory. If you installed it somewhere else, delete that one instead
rm -rf ~/Qt
Then here are the directories with "Qt" in the name that I found on my system
rm -rf ~/Library/Application\ Support/Qt
rm -rf ~/Library/Caches/QtProject
rm -rf ~/.config/QtProject