CHANGELOG.md in cotcube-helpers-0.1.9 vs CHANGELOG.md in cotcube-helpers-0.1.9.1

@@ -1,4 +1,8 @@
+## 0.1.9.1 (May 07, 2021)
+  - moved 'get_id_set' to Cotcube::Helpers
+  - minor fix to suppress some warning during build
+
 ## 0.1.9 (May 07, 2021)
   - added constants, init and symbols to helpers
 
 ## 0.1.8 (April 18, 2021)
   - datetime_ext: Date.cw provides a range of (Date..Date) representing the according calendar week