using Data.Map if containers is old.

hoping passing travis tests.

ghc-mod.cabal

@@ -62,7 +62,7 @@ Library
                         Language.Haskell.GhcMod.List
                         Language.Haskell.GhcMod.Types
   Build-Depends:        base >= 4.0 && < 5
-                      , containers >= 0.5
+                      , containers
                       , directory
                       , filepath
                       , ghc
@@ -99,7 +99,7 @@ Executable ghc-modi
   GHC-Options:          -Wall
   HS-Source-Dirs:       src
   Build-Depends:        base >= 4.0 && < 5
-                      , containers >= 0.5
+                      , containers
                       , directory
                       , filepath
                       , ghc
@@ -129,7 +129,7 @@ Test-Suite spec
                         LintSpec
                         ListSpec
   Build-Depends:        base >= 4.0 && < 5
-                      , containers >= 0.5
+                      , containers
                       , directory
                       , filepath
                       , ghc

src/GHCModi.hs

@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE BangPatterns, CPP #-}
 
 module Main where
 
@@ -8,8 +8,13 @@ import qualified Control.Exception as E (handle, SomeException(..))
 import Control.Monad (when, void)
 import Data.Function
 import Data.List (intercalate, groupBy, sort, find)
+#if MIN_VERSION_containers(0,5,0)
 import Data.Map.Strict (Map)
 import qualified Data.Map.Strict as M
+#else
+import Data.Map (Map)
+import qualified Data.Map as M
+#endif
 import Data.Set (Set)
 import qualified Data.Set as S
 import qualified Exception as G (ghandle)