Only recommend age appropriate badges.
Fix badge fixture.
Recommend offline badges, but bias towards online.
Recommend offline badges.

Though we bias towards online badges, we will now also recommend offline
badges so long as they are active. A program is "active" if it's after
the start date, but before the end date (both inclusive).
Fully populate badges before calling back.
Fix bug, should check for issuer deeply.
Minor refactoring.
More refactoring, adjusting comments.
Merge pull request #183 from mozilla/172-user-recommendations

User badge recommendations, stage 2