yotam: minor aestheti
yotam: refactor popularity_dif into facebook_feed method, with interpolation using pandas , in-construction alert added to homepage
yotam: add is_current field to facebook_feed, and core.management.command  updateiscurrent according to mks data.
yotam: minor changes to under-construction alert
yotam: update fixture files to include is_current data
yotam: create Facebook_FeedManager with current feeds only, refactor get_largest_fan_count_difference into Facebook_FeedManager method.
yotam: clean some printing in commands fetchfeedstatuses and fetchfeedproperties
yotam: update psycopg2 from 2.5.1 to 2.5.3