Merge pull request #1813 from christianv/joyce-changes

NOJIRA - CFV - Changes during the meeting with Joyce
CLC-2780 Followup - include formatted date in last-modified timestamp data
CLC-2780 - Up Next cached feed not refreshed when other widgets are
https://jira.media.berkeley.edu/jira/browse/CLC-2780
CLC-2780 Followup - include formatted date in last-modified timestamp data
by @ctweney
CLC-2780 - Update updated_feeds dummy file with new date format