can: Changelog entry

Author: timokroeger

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased]
 
 ### Added
+- Added `Can` Controller Area Network traits.
 - `Error` traits for SPI, I2C and Serial traits. The error types used in those must
   implement these `Error` traits, which implies providing a conversion to a common
   set of error kinds. Generic drivers using these interfaces can then convert the errors