[changelog] Update for 1.6.1

CHANGELOG.md

@@ -1,6 +1,10 @@
 CHANGELOG
 =========
 
+# 1.6.1 / 2018-03-05
+
+* [BUGFIX] Remove failing import of expired APT key. See [#105][]
+
 # 1.6.0 / 2018-01-19
 
 * [IMPROVEMENT] Refresh apt cache every hour. See [#98][]
@@ -54,6 +58,10 @@ Initial release, compatible with Ansible v1 & v2
 [#68]: https://github.com/DataDog/ansible-datadog/issues/68
 [#80]: https://github.com/DataDog/ansible-datadog/issues/80
 [#81]: https://github.com/DataDog/ansible-datadog/issues/81
+[#90]: https://github.com/DataDog/ansible-datadog/issues/90
+[#98]: https://github.com/DataDog/ansible-datadog/issues/98
+[#105]: https://github.com/DataDog/ansible-datadog/issues/105
+[@brendanlong]: https://github.com/brendanlong
 [@eplanet]: https://github.com/eplanet
 [@geoffwright]: https://github.com/geoffwright
 [@gtrummell]: https://github.com/gtrummell