Fix test errors in windows caused by encoding (#782)

dhall/doctest/Main.hs

@@ -3,12 +3,16 @@ module Main where
 import Data.Monoid ((<>))
 import System.FilePath ((</>))
 
+import qualified GHC.IO.Encoding
 import qualified System.Directory
+import qualified System.IO
 import qualified Test.Mockery.Directory
 import qualified Test.DocTest
 
 main :: IO ()
 main = do
+   
+    GHC.IO.Encoding.setLocaleEncoding System.IO.utf8 
     pwd    <- System.Directory.getCurrentDirectory
     prefix <- System.Directory.makeAbsolute pwd
 

dhall/src/Dhall/Tutorial.hs

@@ -476,7 +476,7 @@ import Dhall
 -- *** Exception: 
 -- ↳ ./baz: 
 -- ...
--- ...Error...: Missing file .../baz:
+-- ...Error...: Missing file ...baz:
 -- ...
 --
 -- This is because the parser thinks that @./baz:@ is a single token due to

dhall/tests/Dhall/Test/Main.hs

@@ -11,8 +11,10 @@ import qualified Dhall.Test.QuickCheck
 import qualified Dhall.Test.Regression
 import qualified Dhall.Test.Tutorial
 import qualified Dhall.Test.TypeCheck
+import qualified GHC.IO.Encoding
 import qualified System.Directory
 import qualified System.Environment
+import qualified System.IO
 import qualified Test.Tasty
 
 import System.FilePath ((</>))
@@ -33,6 +35,8 @@ allTests =
 
 main :: IO ()
 main = do
+
+    GHC.IO.Encoding.setLocaleEncoding System.IO.utf8
     pwd <- System.Directory.getCurrentDirectory
     System.Environment.setEnv "XDG_CACHE_HOME" (pwd </> ".cache")
     Test.Tasty.defaultMain allTests