CHANGELOG.md in govuk_app_config-1.5.1 vs CHANGELOG.md in govuk_app_config-1.6.0

@@ -1,4 +1,9 @@
+# 1.6.0
+
+* Make health checks classes rather than instances, allowing internal data to
+  be cached and improve performance.
+
 # 1.5.1
 
 * Set the `Content-Type` of healthchecks to `application/json`.
 * Make the health check statuses symbols.