Add Celebrity Recognition Tab

[dylancaponi]

Fixes #6.

Clones logo_recognition.js as celebrity_recognition and adds some minor modifications for the differing hierarchy in celebrity feature data.

Testing Tested with Video Intelligence JSON output containing celebrity recognition feature data. Not sure what the ToS is on sharing these sample outputs. Let me know if you need this before merging.

Caveats For some reason, some outputs contained confidence keys while others did not. Thus I pass along elements that either were above the confidence threshold or do not have one at all.