feature #7: add find_comment_by_id query

src/main/resources/sql/fixtures/01-user.sql

@@ -8,7 +8,7 @@ begin
     insert into "user" (id, username, password, blocked_at, roles)
     select
         uuid_in(md5('user'||rn::text)::cstring),
-        'username' || rn,
+        'username-' || rn,
         _password,
         case when rn % 10 = 0 then now() else null end,
         case when rn % 2 = 0 then '{ROLE_USER}'::text[] else '{ROLE_ADMIN}'::text[] end