Enforce GHC >= 7.10 and fix Stack warnings

src/PostgREST/Auth.hs

@@ -18,9 +18,6 @@ module PostgREST.Auth (
   , tokenJWT
   ) where
 
---line needed for ghc 7.8
-import           Data.Functor            ((<$>))
- 
 import           Data.Aeson              (Value (..), Object)
 import           Data.Aeson.Types        (emptyObject, emptyArray)
 import           Data.Vector             as V (null, head)

src/PostgREST/Middleware.hs

@@ -3,9 +3,6 @@
 
 module PostgREST.Middleware where
 
--- needed for ghc 7.8
-import           Data.Functor ((<$>))
-
 import           Data.Maybe                    (fromMaybe, isNothing)
 import           Data.Monoid
 import           Data.Text

src/PostgREST/Parsers.hs

@@ -4,10 +4,6 @@ module PostgREST.Parsers
 where
 
 import           Control.Applicative hiding ((<$>))
---lines needed for ghc 7.8
-import           Data.Functor ((<$>))
-import           Data.Traversable (traverse)
-
 import           Control.Monad                 (join)
 import           Data.List                     (delete, find)
 import           Data.Maybe