hookup_manager stage one:  New tables for pending and active hookups (pair programming events).  Pivotal #75025008, 75025492

New tables for pending and active hookups (pair programming events).
Pivotal stories:
 "display list of pending events in a table", https://www.pivotaltracker.com/s/projects/982890/stories/75025008, and 
"display list of active/live hookups (i.e. hookups with live hangouts) in a separate table",https://www.pivotaltracker.com/s/projects/982890/stories/75025492. 
Added a hookups view, a hookups controller with an index service, and several methods to the events model to distinguish pending, active, and expired events.
if something is under "Pending Hookups", with this implementation, won't it also mean it is 'under' "Active Hookups"?