Remove unused imports (with newer protolude)

The changes here are from fixing stack build with LTS 15.8 (GHC 8.8.3)
to be warning-free. Most if not all come from the newer protolude
version, which adds some things like `unwords`.

So to make sure that we don't get unused import warnings with newer
stackage, this both raises the protolude lower bound and removes
these imports.

src/PostgREST/ApiRequest.hs

@@ -28,8 +28,8 @@ import qualified Data.Vector          as V
 
 import Control.Arrow             ((***))
 import Data.Aeson.Types          (emptyArray, emptyObject)
-import Data.List                 (elem, last, lookup, partition)
-import Data.List.NonEmpty        (NonEmpty, head)
+import Data.List                 (last, lookup, partition)
+import Data.List.NonEmpty        (head)
 import Data.Maybe                (fromJust)
 import Data.Ranged.Ranges        (Range (..), emptyRange,
                                   rangeIntersection)

src/PostgREST/App.hs

@@ -40,7 +40,6 @@ import Network.HTTP.Types.Status
 import Network.Wai
 
 import PostgREST.ApiRequest       (Action (..), ApiRequest (..),
-                                   ContentType (..),
                                    InvokeMethod (..), Target (..),
                                    mutuallyAgreeable, userApiRequest)
 import PostgREST.Auth             (containsRole, jwtClaims,

src/PostgREST/Config.hs

@@ -37,12 +37,11 @@ import Control.Lens                (preview)
 import Control.Monad               (fail)
 import Crypto.JWT                  (StringOrURI, stringOrUri)
 import Data.List                   (lookup)
-import Data.List.NonEmpty          (NonEmpty, fromList)
+import Data.List.NonEmpty          (fromList)
 import Data.Scientific             (floatingOrInteger)
 import Data.Text                   (dropEnd, dropWhileEnd,
-                                    intercalate, lines, splitOn,
-                                    strip, take, unpack)
-import Data.Text.Encoding          (encodeUtf8)
+                                    intercalate, splitOn, strip, take,
+                                    unpack)
 import Data.Text.IO                (hPutStrLn)
 import Data.Version                (versionBranch)
 import Development.GitRev          (gitHash)

src/PostgREST/Error.hs

@@ -23,7 +23,6 @@ import qualified Network.HTTP.Types.Status as HT
 
 import Data.Aeson  ((.=))
 import Network.Wai (Response, responseLBS)
-import Text.Read   (readMaybe)
 
 import Network.HTTP.Types.Header
 

src/PostgREST/Parsers.hs

@@ -9,10 +9,8 @@ module PostgREST.Parsers where
 import qualified Data.HashMap.Strict as M
 import qualified Data.Set            as S
 
-import Control.Monad           ((>>))
 import Data.Either.Combinators (mapLeft)
 import Data.Foldable           (foldl1)
-import Data.Functor            (($>))
 import Data.List               (init, last)
 import Data.Text               (intercalate, replace, strip)
 import Text.Read               (read)

src/PostgREST/Private/QueryFragment.hs

@@ -11,7 +11,7 @@ import qualified Data.HashMap.Strict           as HM
 import           Data.Maybe
 import           Data.Text                     (intercalate,
                                                 isInfixOf, replace,
-                                                toLower, unwords)
+                                                toLower)
 import qualified Data.Text                     as T (map, null,
                                                      takeWhile)
 import           PostgREST.Types

src/PostgREST/QueryBuilder.hs

@@ -22,7 +22,7 @@ module PostgREST.QueryBuilder (
 
 import qualified Data.Set as S
 
-import Data.Text (intercalate, unwords)
+import Data.Text (intercalate)
 import Data.Tree (Tree (..))
 
 import Data.Maybe

src/PostgREST/Statements.hs

@@ -22,8 +22,6 @@ import           Data.Aeson                      as JSON
 import qualified Data.Aeson.Lens                 as L
 import qualified Data.ByteString.Char8           as BS
 import           Data.Maybe
-import           Data.Text                       (unwords)
-import           Data.Text.Encoding              (encodeUtf8)
 import qualified Hasql.Decoders                  as HD
 import qualified Hasql.Encoders                  as HE
 import qualified Hasql.Statement                 as H