Don't let pkgdb2 errors turn into false positives.

Fixes a bug found by @bochecha where he was awarded the Helping Hand badge
erroneously.

The bug starts with getting a non-200 status code from pkgdb2.  fedbadges would
then incorrectly coerce that response to mean "if pkgdb2 gave an error when
asking for USER's packages, then USER must have 0 packages".  If USER then goes
to rebuild a package they own while pkgdb2 is erroring out temporarily, then
fedbadges concluceds that USER is rebuilding a package they do not own (since
fedbadges thinks that USER owns 0 packages).

This patch adjusts it so that if an IOError is raised from one of the criteria
comparators, then badge awarding will abort all together.