refactor: add planCost and planHdr for tests

postgrest.cabal

@@ -242,6 +242,7 @@ test-suite spec
                     , process           >= 1.4.2 && < 1.7
                     , protolude         >= 0.3.1 && < 0.4
                     , regex-tdfa        >= 1.2.2 && < 1.4
+                    , scientific        >= 0.3.4 && < 0.4
                     , text              >= 1.2.2 && < 1.3
                     , transformers-base >= 0.4.4 && < 0.5
                     , wai               >= 3.2.1 && < 3.3