CLC-1796 Change Task bucket structure per new designs

JIRA: https://jira.media.berkeley.edu/jira/browse/CLC-1796

The feed returns a maximum of 10 items in the "Future" bucket. 

I modified the front-end code so that it uses the new feed structure. 

However, the "show X more" functionality was beyond my understanding of angular. I'll leave that to a front-end dev.