Changelog. Update

Author: andrykonchin

CHANGELOG.md

@@ -8,10 +8,12 @@
 
 * Improvement: [#359](https://github.com/Dynamoid/dynamoid/pull/359) Add support of `NULL` and `NOT_NULL` operators
 * Improvement: [#360](https://github.com/Dynamoid/dynamoid/pull/360) Add `store_attribute_with_nil_value` config option
+* Improvement: [#368](https://github.com/Dynamoid/dynamoid/pull/368) Support Rails 6 (RC1)
 
 ## Fixes
 * Fix: [#357](https://github.com/Dynamoid/dynamoid/pull/357) Fix synchronous table creation issue
 * Fix: [#362](https://github.com/Dynamoid/dynamoid/pull/362) Fix issue with selecting Global Secondary Index (@atyndall)
+* Fix: [#368](https://github.com/Dynamoid/dynamoid/pull/368) Repair `#previous_changes` method from Dirty API
 
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