Minor 6.3.0 beta1 changes (#18048)

* chore: mirror the Dockerhub readme

Seems like the dockerhub readme is out of sync with this one. Let's update this one to make them identical.

* chore: add changes part of 6.3.0-beta1 to the docker image README

* chore: add the date to the 6.3.0-beta1 changes in the CHANGELOG

CHANGELOG.md

@@ -1,6 +1,6 @@
 # 6.4.0 (unreleased)
 
-# 6.3.0-beta1
+# 6.3.0-beta1 (2019-07-10)
 ### Features / Enhancements
 * **Alerting**: Add tags to alert rules. [#10989](https://github.com/grafana/grafana/pull/10989), [@Thib17](https://github.com/Thib17)
 * **Alerting**: Attempt to send email notifications to all given email addresses. [#16881](https://github.com/grafana/grafana/pull/16881), [@zhulongcheng](https://github.com/zhulongcheng)

packaging/docker/README.md

@@ -16,6 +16,18 @@ Further documentation can be found at http://docs.grafana.org/installation/docke
 
 ## Changelog
 
+### v6.3.0-beta1
+* Docker: Switch base image to ubuntu:latest from debian:stretch to avoid security issues.
+
+### v5.4.3
+* Build and publish docker images for armv7 and arm64 #14617, thx @johanneswuerbach
+
+### v5.3.2
+* adds curl back into the docker image for utility. #13794
+
+### v5.3.0-beta1
+* Make it possible to set a specific plugin url #12861, thx ClementGautier
+
 ### v5.1.5, v5.2.0-beta2
 * Fix: config keys ending with _FILE are not respected [#170](https://github.com/grafana/grafana-docker/issues/170)