CHANGELOG.md in ndr_support-5.5.0 vs CHANGELOG.md in ndr_support-5.5.1

@@ -1,7 +1,13 @@
 ## [Unreleased]
 *no unreleased changes*
 
+## 5.5.1 / 2019-05-15
+### Fixed
+* Support Ruby 2.6, Rails 6.0. Minimum Ruby/Rails versions are now 2.5/5.2
+* Warn when WorkingDays lookup is getting stale
+* Improved date parsing in String#to_date
+
 ## 5.5.0 / 2018-11-16
 ### Added
 * Add `ThreatScanner` to wrap ClamAV for virus detection (#10)
 
 ### Fixed