Allow warp 3.4

Builds fine and all tests pass here.

Author: felixonmars

HTTP.cabal

@@ -188,7 +188,7 @@ Test-Suite test
       , conduit             >= 1.0.8    && < 1.4
       , http-types          >= 0.8.0    && < 1.0
       , wai                 >= 2.1.0    && < 3.3
-      , warp                >= 2.1.0    && < 3.4
+      , warp                >= 2.1.0    && < 3.5
 
     if flag(conduit10)
       build-depends: conduit < 1.1