[Database] cleaning unused instances.

src/Gargantext/Database/Instances.hs

-{-|
-Module      : Gargantext.Database.Instances
-Description : 
-Copyright   : (c) CNRS, 2017-Present
-License     : AGPL + CECILL v3
-Maintainer  : team@gargantext.org
-Stability   : experimental
-Portability : POSIX
-
-Here is a longer description of this module, containing some
-commentary with @some markup@.
--}
-
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-
-{-# LANGUAGE FlexibleInstances     #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE NoImplicitPrelude     #-}
-
-module Gargantext.Database.Instances where
-
-import Gargantext.Prelude
-
-import Data.Text (Text)
-import Data.Time (UTCTime)
-
-import Opaleye (PGInt4, PGTimestamptz, PGFloat8
-               , QueryRunnerColumnDefault
-               , queryRunnerColumnDefault
-               , fieldQueryRunnerColumn
-               , Nullable, PGText)
-
-instance QueryRunnerColumnDefault PGInt4 Integer where
-    queryRunnerColumnDefault = fieldQueryRunnerColumn
-
-instance QueryRunnerColumnDefault PGFloat8 (Maybe Double) where
-    queryRunnerColumnDefault = fieldQueryRunnerColumn
-
-instance QueryRunnerColumnDefault PGInt4 (Maybe Int) where
-    queryRunnerColumnDefault = fieldQueryRunnerColumn
-
-instance QueryRunnerColumnDefault PGTimestamptz (Maybe UTCTime) where
-  queryRunnerColumnDefault = fieldQueryRunnerColumn
-
-instance QueryRunnerColumnDefault (Nullable PGInt4) Int where
-    queryRunnerColumnDefault = fieldQueryRunnerColumn
-
-instance QueryRunnerColumnDefault (Nullable PGText) Text    where
-  queryRunnerColumnDefault = fieldQueryRunnerColumn
-