test(spec): inline config into test suite

Previously, information about each test-suite was repeated in 3 separate
places:
- as a label and as implicit knowledge in the test-suite itself,
- as a comment in Main.hs, and
- as a configuration in SpecHelper.hs.

With this change, there will be a single source of truth in the test
suite itself. This will allow a single test-suite to easily test
multiple different configurations.

test/spec/Feature/Query/QuerySpec.hs

@@ -1,6 +1,5 @@
 module Feature.Query.QuerySpec where
 
-import Network.Wai      (Application)
 import Network.Wai.Test (SResponse (simpleHeaders))
 
 import Network.HTTP.Types
@@ -11,8 +10,8 @@ import Test.Hspec.Wai.JSON
 import Protolude  hiding (get)
 import SpecHelper
 
-spec :: SpecWith ((), Application)
-spec = do
+spec :: SpecWithConfig
+spec withConfig = withConfig baseCfg $ do
 
   describe "Querying a table with a column called count" $
     it "should not confuse count column with pg_catalog.count aggregate" $