User accounts have a Time Zone

Users' Time Zone is set as the default when creating events.
Taking another stab at auto-installing PhantomJS 1.8.2 on CI
Remove outdated ruby/rails references from readme. Rrrrr.
Merge branch 'master' of https://github.com/lilliealbert/bridge_troll into lilliealbert-master
Added test event to things created by db:seed
Remove numerous events_helper functions for displaying or sorting volunteers

All ActiveHash classes (Role, VolunteerAssignment, and now VolunteerPreference) now use
ActiveHash::Enum instead of hand-defined constants. This means now if you want a role_id
you have to do Role::VOLUNTEER.id, because Role::VOLUNTEER is a role instance.
added volunteer details textarea to new event form

[fixes #45628531]
fixed broken css selectors in spec.  have no idea why they were passing before
Organizer dashboard shows number of checked in RSVPers per session.
Add link to GitHub issues in nav bar