Merge pull request #204 from coyote/clean_vimeo_data

CYB-335 script to populate empty vimeo thumbnail_url fields
CYB-324 Refactor Gallery API

    CYB-324 CYB-338 CYB-339

    Refactor Gallery API to make it run much faster.
    Now it uses pure SQL to get the data, and iterates over it in Ruby to
      make the format better for the API
    CYB-338 and CYB-339 were too closely tied together to do separately.

    https://jira.ets.berkeley.edu/jira/browse/CYB-324
    https://jira.ets.berkeley.edu/jira/browse/CYB-339
    https://jira.ets.berkeley.edu/jira/browse/CYB-339