Revert "test(pandoc): temporarily disable failing test for applyMetas -- to be reverted and properly fixed"

This reverts commit 3081e61e02.

test/PandocSpec.hs

@@ -44,7 +44,7 @@ instance Arbitrary ArbitraryMeta where
 spec :: Spec
 spec = do
   let mlist = Map.toAscList . unMeta
-  {- TODO
+
   describe "applyMetas" $ do
     it "should actually set values" $ do
       (ml, abMetaOriginal, blocks) <- generate arbitrary
@@ -65,7 +65,7 @@ spec = do
         oldm = [(k,t) | (k, t) <- mlist metaOriginal , Set.member k nullKeys]
         newm = [(k,t) | (k, t) <- mlist newMeta      , Set.member k nullKeys]
       oldm `shouldMatchList` newm
-  -}
+
   describe "addMeta" $ do
     it "should possibly overwrite existing settings" $ do
       (abMetaOverwrite, abMetaOriginal, blocks) <- generate arbitrary