update changelog for 0.8.0

Author: mcwhittemore

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Change Log
 All notable changes to this project will be documented in this file. For change log formatting, see http://keepachangelog.com/
 
-## master
+## 0.8.0 2017-10-04
 
 - Added grammatical cases support for Russian way names [#102](https://github.com/Project-OSRM/osrm-text-instructions/pull/102)
 - Adds `osrmti.getWayName` to the public api. You MUST NOT change the result before passing it into `osrmti.tokenize`. [#167](https://github.com/Project-OSRM/osrm-text-instructions/pull/167)