Add #120 to History.md

Author: mattwynne

HISTORY.md

@@ -2,6 +2,7 @@
 
 ### New Features
 
+ * Ruby 2.4.0 compatability ([#120](https://github.com/cucumber/cucumber-ruby-core/pull/120) @junaruga)
  * Implement equality for test cases ([#111](https://github.com/cucumber/cucumber-ruby-core/pull/111) @mattwynne)
  * Implement an event bus (moved from Cucumber-Ruby) ([#106](https://github.com/cucumber/cucumber-ruby-core/pull/106) @mattwynne)
  * Use frozen string literals ([#105](https://github.com/cucumber/cucumber-ruby-core/pull/105) @twalpole)