Removed safe library from dependencies

postgres-wire.cabal

@@ -43,7 +43,6 @@ library
                      , socket
                      , socket-unix
                      , vector
-                     , safe
                      , time
                      , hashable
                      , hashtables

src/Database/PostgreSQL/Driver/RawConnection.hs

@@ -6,7 +6,6 @@ module Database.PostgreSQL.Driver.RawConnection
 
 import Control.Monad (void, when)
 import Control.Exception (bracketOnError, try)
-import Safe (headMay)
 import Data.Monoid ((<>))
 import Foreign (castPtr, plusPtr)
 import System.Socket (socket, AddressInfo(..), getAddressInfo, socketAddress,
@@ -75,6 +74,9 @@ createRawConnection settings
         let dir = B.reverse . B.dropWhile (== 47) $ B.reverse dirPath
         in dir <> "/" <> unixPathFilename <> portStr
 
+    headMay []    = Nothing
+    headMay (x:_) = Just x
+
 constructRawConnection :: Socket f Stream p -> RawConnection
 constructRawConnection s = RawConnection
     { rFlush = pure ()