add debug logging about bstore db schema upgrades

bstore was updated to v0.0.6 to add this logging.
this simplifies some of the db-handling code in mtastsdb,tlsrptdb,dmarcdb. we
now call the package-level Init() and Close() in all tests properly.

queue/suppression_test.go

@@ -10,8 +10,6 @@ import (
 func TestSuppression(t *testing.T) {
 	_, cleanup := setup(t)
 	defer cleanup()
-	err := Init()
-	tcheck(t, err, "queue init")
 
 	l, err := SuppressionList(ctxbg, "bogus")
 	tcheck(t, err, "listing suppressions for unknown account")