Add common instances to Req module.

servant-client/src/Servant/Common/Req.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE DeriveGeneric       #-}
 {-# LANGUAGE CPP                 #-}
 {-# LANGUAGE OverloadedStrings   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -12,14 +13,16 @@ import Control.Monad
 import           Control.Monad.Catch        (MonadThrow)
 import           Control.Monad.IO.Class
 import           Control.Monad.Trans.Either
-import Data.ByteString.Lazy hiding (pack, filter, map, null, elem)
+import           Data.ByteString.Lazy       hiding (elem, filter, map, null,
+                                             pack)
 import           Data.IORef
+import           Data.Proxy
 import           Data.String
 import           Data.String.Conversions
-import Data.Proxy
 import           Data.Text                  (Text)
 import           Data.Text.Encoding
 import           Data.Typeable
+import           GHC.Generics
 import           Network.HTTP.Client        hiding (Proxy)
 import           Network.HTTP.Client.TLS
 import           Network.HTTP.Media
@@ -55,7 +58,7 @@ data ServantError
   | ConnectionError
     { connectionError           :: SomeException
     }
-  deriving (Show, Typeable)
+  deriving (Eq, Show, Typeable, Generic)
 
 instance Exception ServantError
 
@@ -65,7 +68,7 @@ data Req = Req
   , reqBody   :: Maybe (ByteString, MediaType)
   , reqAccept :: [MediaType]
   , headers   :: [(String, Text)]
-  }
+  } deriving (Eq, Show, Typeable, Generic)
 
 defReq :: Req
 defReq = Req "" [] Nothing [] []