It does not work well with turbo frames that error out during
development, since it changes the URL on the error to the location of
the frame. Find that more annoying than I find Spark helpful.
- rails console will have the current tenant set to ARTENANT if set, else the default
- current tenant can be set via concrete classes, e.g. `User.current_tenant = "foo"`
- we no longer need to explicitly add the TenantSelector middleware
- and we can set up a properly-articulated tenant resolver proc that's
used by both TenantSelector and Action Cable connections
ref: https://37s.fizzy.37signals.com/buckets/693169862/bubbles/999008671