HISTORY.md in strong_actions-0.0.8 vs HISTORY.md in strong_actions-0.0.9

@@ -1,6 +1,9 @@
 # History
 
+## 0.0.9
+* fixed thread safety issue on multi-thread environment.
+
 ## 0.0.8
 * drop support for rails-4.0
 * add support for rails-5.0
 
 ## 0.0.7