Release 20190610 of the `datalab` command line tool.

[yunluyl]

This is a tracking issue for the 20170610 release of the datalab command line tool.

This issue will be used to report the source of the tool, it's changes, and when it is incorporated into the Google Cloud SDK

Source
The commit of the release is d6ddeac
A tarball of the CLI tool release can be downloaded by running:

gsutil cp gs://cloud-datalab/builds/datalab-cli-d6ddeac5639aecddc0dae56f69fd7de4e159690c.tgz ./
The following changes are included in this release:

Bug Fixes:
#2134: Added Shared VPC Support