update changelog

Author: ph

CHANGELOG.md

@@ -0,0 +1,5 @@
+## 2.0.0
+ - Plugins were updated to follow the new shutdown semantic, this mainly allows Logstash to instruct input plugins to terminate gracefully, 
+   instead of using Thread.raise on the plugins' threads. Ref: https://github.com/elastic/logstash/pull/3895
+ - Dependency on logstash-core update to 2.0
+