single db with prefixes, dump/restore, blacklisting on user deletion

pkg/db/lockout.go

@@ -0,0 +1,11 @@
+package db
+
+const lockoutPrefix = "lockout/"
+
+func (db *DB) lockout(username, created string) error {
+	return db.store.Set(lockoutPrefix+username+created, nil)
+}
+
+func (db *DB) LockedOut(username, created string) bool {
+	return db.store.Get(lockoutPrefix+username+created, nil) == nil
+}