Updating CHANGELOG for google-cloud package. (#4302)

Author: dhermes

CHANGELOG.md

@@ -6,4 +6,34 @@
 
 ## 0.28.0
 
-Placeholder
+Packages newly added to the `google-cloud` umbrella package:
+
+- [`google-api-core==0.1.1`](https://pypi.org/project/google-api-core/0.1.1/)
+- [`google-cloud-firestore==0.28.0`](https://pypi.org/project/google-cloud-firestore/0.28.0/)
+- [`google-cloud-trace==0.16.0`](https://pypi.org/project/google-cloud-trace/0.16.0/)
+- [`google-cloud-videointelligence=0.28.0`](https://pypi.org/project/google-cloud-videointelligence/0.28.0/)
+
+Feature / bugfix releases for the following packages:
+
+- [`google-cloud-bigquery==0.28.0`](https://pypi.org/project/google-cloud-bigquery/0.28.0/)
+- [`google-cloud-core==0.28.0`](https://pypi.org/project/google-cloud-core/0.28.0/)
+- [`google-cloud-datastore==1.4.0`](https://pypi.org/project/google-cloud-datastore/1.4.0/)
+- [`google-cloud-logging==1.4.0`](https://pypi.org/project/google-cloud-logging/1.4.0/)
+- [`google-cloud-pubsub==0.29.0`](https://pypi.org/project/google-cloud-pubsub/0.29.0/)
+- [`google-cloud-spanner==0.29.0`](https://pypi.org/project/google-cloud-spanner/0.29.0/)
+- [`google-cloud-translate==1.3.0`](https://pypi.org/project/google-cloud-translate/1.3.0/)
+- [`google-cloud-vision==0.28.0`](https://pypi.org/project/google-cloud-vision/0.28.0/)
+
+Dependency-only / user-invisible changes to the following packages:
+
+- [`google-cloud-bigtable==0.28.0`](https://pypi.org/project/google-cloud-bigtable/0.28.0/)
+- [`google-cloud-dns==0.28.0`](https://pypi.org/project/google-cloud-dns/0.28.0/)
+- [`google-cloud-error-reporting==0.28.0`](https://pypi.org/project/google-cloud-error-reporting/0.28.0/)
+- [`google-cloud-language==0.30.0`](https://pypi.org/project/google-cloud-language/0.30.0/)
+- [`google-cloud-monitoring==0.28.0`](https://pypi.org/project/google-cloud-monitoring/0.28.0/)
+- [`google-cloud-resource-manager==0.28.0`](https://pypi.org/project/google-cloud-resource-manager/0.28.0/)
+- [`google-cloud-runtimeconfig==0.28.0`](https://pypi.org/project/google-cloud-runtimeconfig/0.28.0/)
+- [`google-cloud-speech==0.30.0`](https://pypi.org/project/google-cloud-speech/0.30.0/)
+- [`google-cloud-storage==1.6.0`](https://pypi.org/project/google-cloud-storage/1.6.0/)
+
+PyPI: https://pypi.org/project/google-cloud/0.28.0/