Remove lint allow statements for markup5ever (servo#653)

Signed-off-by: Simon Wülker <[email protected]>

Author: simonwuelker

markup5ever/interface/mod.rs

@@ -168,7 +168,6 @@ pub mod tree_builder;
 /// NOTE: `Prefix`, `LocalName` and `Prefix` all implement `Deref<str>`.
 ///
 #[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone)]
-#[cfg_attr(feature = "heap_size", derive(HeapSizeOf))]
 pub struct QualName {
     /// The prefix of qualified (e.g. `furn` in `<furn:table>` above).
     /// Optional (since some namespaces can be empty or inferred), and

markup5ever/lib.rs

@@ -7,10 +7,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unexpected_cfgs)]
-// This error is coming from code generated by PHF which we cannot directly fix
-#![allow(clippy::empty_line_after_doc_comments)]
-
 pub use tendril;
 
 #[macro_use]