Add entry to `CHANGELOG.md` and fix typo

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## Fixed
 
  * `type_object::PyTypeObject` has been marked unsafe because breaking the contract `type_object::PyTypeObject::init_type` can lead to UB.
+ * Fixed automatic derive of `PySequenceProtocol` implementation in [#423](https://github.com/PyO3/pyo3/pull/423).
 
 ## [0.6.0] - 2018-03-28
 

src/class/sequence.rs

@@ -14,7 +14,7 @@ use crate::Python;
 use crate::{FromPyObject, IntoPyObject};
 use std::os::raw::c_int;
 
-/// Sequece interface
+/// Sequence interface
 #[allow(unused_variables)]
 pub trait PySequenceProtocol<'p>: PyTypeInfo + Sized {
     fn __len__(&'p self) -> Self::Result