tests: Unset http_proxy environment variable

Closes: erikd#8

Test/testsuite.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE OverloadedStrings #-}
 ------------------------------------------------------------
 -- Copyright : Erik de Castro Lopo <[email protected]>
@@ -12,6 +13,7 @@ import Control.Monad.Trans.Resource
 import Data.Conduit
 import Data.Int (Int64)
 import Data.Monoid
+import System.Environment
 import Test.Hspec
 import Test.Hspec.QuickCheck
 
@@ -37,7 +39,12 @@ proxyTestDebug :: Bool
 proxyTestDebug = False
 
 main :: IO ()
-main =
+main = do
+#if __GLASGOW_HASKELL__ > 706
+    -- Clear the `http_proxy` enviroment variable. We can't use `unsetEnv` if
+    -- we want to support ghc 7.6.
+    unsetEnv "http_proxy"
+#endif
     bracket
         (mapM async [ runTestServer, runTestServerTLS ])
         (mapM_ cancel)