Fix relative UW funnel numbers

The script relied on the (apparently false) assumption that there
are always more tutorial steps than file steps etc. This resulted
in the wrong step counts used for the ratios. We order the steps
manually now to avoid such issues.

Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/862
Change-Id: Ic92978fbce45caa0ea58ad6d8ba56fb2bf8354c7