2018 Metrics report

One more thing.

In the report there is a slide called “Top 40 Downloaded Packages”.
Not surprisingly, it seems that the packages in the top 40 are those installed by default by either
ros-DISTRO-desktop or ros-DISTRO-base.

It would be nice if we can get the top 40 excluding the packages already included in ros-DISTRO-desktop.

And by the way, thanks @tfoote for giving us the metrics.