Fix typos
Add helper subroutine to extract <link rel="canonical" /> from HTML
Refactor subroutine to have a single return point
If <link rel="canonical" /> is present, check it against Bit.ly API too
Return arrayref (instead of hashref) of categories because it makes more sense
Fix formatting
Split bitly_link_lookup_all_variants() into bitly_link_lookup_hashref() and bitly_link_lookup_hashref_all_variants() for consistency
Change order so that exception with "categories" is more visible
Fetch link info (via "/v3/info" API call) for each Bit.ly link because we're probably need the creation timestamp of each link