Don't re-export as by default (#83)

To continue using it, import it from `Witch.Utility`.

source/library/Witch.hs

@@ -34,7 +34,6 @@ module Witch
     Witch.Encoding.UTF_32BE,
 
     -- * Utilities
-    Witch.Utility.as,
     Witch.Utility.via,
     Witch.Utility.tryVia,
     Witch.Utility.maybeTryFrom,

source/test-suite/Main.hs

@@ -56,7 +56,7 @@ spec = describe "Witch" $ do
   describe "Utility" $ do
     describe "as" $ do
       it "works" $ do
-        Witch.as @Int.Int8 1 `shouldBe` 1
+        Utility.as @Int.Int8 1 `shouldBe` 1
 
     describe "into" $ do
       it "works" $ do