Fix intermittently-failing hits import spec

* before :all happens once
* it doesn't matter how many nested contexts you have
* for the case where we were nesting before :all, remove
  and go to a simple before(:each). We can't use before(:each)
  for *everything* in this spec, because it triples the time to
  execute (and these are already not quick). But we can and should
  use it for any case where we might have been tempted to nest
  before :all's
* Don't cross the streams!