Add missing imports for later GHC versions

ShellCheck.cabal

@@ -54,11 +54,12 @@ library
       Diff >= 0.2.0,
       directory >= 1.2.3.0,
       fgl,
-      mtl >= 2.2.1,
       filepath,
+      mtl >= 2.2.1,
       parsec,
-      regex-tdfa,
       QuickCheck >= 2.7.4,
+      regex-tdfa,
+      transformers,
       -- When cabal supports it, move this to setup-depends:
       process
     exposed-modules:
@@ -112,6 +113,7 @@ executable shellcheck
       parsec >= 3.0,
       QuickCheck >= 2.7.4,
       regex-tdfa,
+      transformers,
       ShellCheck
     default-language: Haskell98
     main-is: shellcheck.hs
@@ -128,11 +130,12 @@ test-suite test-shellcheck
       Diff >= 0.2.0,
       directory >= 1.2.3.0,
       fgl,
-      mtl >= 2.2.1,
       filepath,
+      mtl >= 2.2.1,
       parsec,
       QuickCheck >= 2.7.4,
       regex-tdfa,
+      transformers,
       ShellCheck
     default-language: Haskell98
     main-is: test/shellcheck.hs

shellcheck.hs

@@ -34,6 +34,8 @@ import qualified ShellCheck.Formatter.Quiet
 
 import           Control.Exception
 import           Control.Monad
+import           Control.Monad.IO.Class
+import           Control.Monad.Trans.Class
 import           Control.Monad.Except
 import           Data.Bits
 import           Data.Char

src/ShellCheck/AnalyzerLib.hs

@@ -32,6 +32,7 @@ import ShellCheck.Regex
 
 import Control.Arrow (first)
 import Control.DeepSeq
+import Control.Monad
 import Control.Monad.Identity
 import Control.Monad.RWS
 import Control.Monad.State

src/ShellCheck/Fixer.hs

@@ -23,6 +23,7 @@ module ShellCheck.Fixer (applyFix, removeTabStops, mapPositions, Ranged(..), run
 
 import ShellCheck.Interface
 import ShellCheck.Prelude
+import Control.Monad
 import Control.Monad.State
 import Data.Array
 import Data.List