fix warnings

Signed-off-by: Sean Cross <sean@xobs.io>

src/lib.rs

@@ -2,18 +2,14 @@
 #![deny(const_err)]
 #![deny(dead_code)]
 #![deny(improper_ctypes)]
-#![deny(legacy_directory_ownership)]
 #![deny(missing_docs)]
 #![deny(no_mangle_generic_items)]
 #![deny(non_shorthand_field_patterns)]
 #![deny(overflowing_literals)]
 #![deny(path_statements)]
 #![deny(patterns_in_fns_without_body)]
-#![deny(plugin_as_library)]
 #![deny(private_in_public)]
-#![deny(safe_extern_statics)]
 #![deny(unconditional_recursion)]
-#![deny(unions_with_drop_fields)]
 #![deny(unused_allocation)]
 #![deny(unused_comparisons)]
 #![deny(unused_parens)]