Fix venueless token creation

Do not generate token or checkin if user does not have a ticket.
Clear existing token if user no longer has a ticket.

Update Venueless tokens

Determine traits based on ticket type.
Set different expiry of token for miniconf only tickets.

Add Venueless integration to Regidesk

Create Venueless login token as part of checkin to allow attendee to
join an online event from the dashboard.

Update to Django 2.2

Upgrade site and modules to Django 2.2. Remove and replace obsolete
functionality with current equivalents. Update requirements to latest
versions where possible. Remove unused dependencies.

Update mobile schedule

Display track details on talks if available.
Show day end time slot as per desktop view.

Styling for schedule

Update to Bootstrap 4 throughout.
Remove unused blocks and elements from past conferences.
Ensure schedule works in print mode.

Fix display of GST amount

Move GST rate to settings. Set to Australian GST rate.

Badges work by copy-pasting lca2017/pyconau2017 code around

WIP - Push for share

If there are no track names for today, don't show the row

If there are track names today, show the row for track names. If there aren't, don't show an empty row.

The 2018ificiation

I think this removes most references to "hobart", "pycon", and "2017"

There are still some references to some images that we don't have a
replacement for.