Make the tracker packages optional to handle when they are missing

• Make the tracker packages optional to handle when they are missing

When loading some of the older releases in testing, there would be missing packages which skewed the tests. This change will allow those entries to properly load as best as possible.

requested review from @cguindon, @malowe, and @zacharysabourin

approved this merge request

mentioned in commit 4a1bdeac

merged