chore(deps): update dependency google-cloud-core to v1.3.0 [(#3066)](GoogleCloudPlatform/python-docs-samples#3066)

Author: renovate-bot

samples/hello/requirements.txt

@@ -1,2 +1,2 @@
 google-cloud-bigtable==1.2.1
-google-cloud-core==1.1.0
+google-cloud-core==1.3.0