Add new SolveBio "Dashboard" to variant detail view

Remove SolveBio requests from variant resource.
Bundles in the SolveBio JS library which loads the dashboard iframe.
Using the new dashboard view requires the solvebio python module >= 1.5.2 and app credentials.
The JS view obtains a SolveBio OAuth2 token from a view within the django_solvebio app (part of the solvebio module). The Dashboard runs in an iframe which is a locally rendered template (variant-detail.html).
This code is still very rough around the edges and updates will be made in the next few days.

Signed-off-by: David Caplan <dcaplan@gmail.com>
Calling `get` defaults to `None`, so using `None` as the default value is redundant.