Beta v20180110

Daisy

CreateImages step can use SourceImage
Add validation of RawDisk.Source to CreateImages
Add DeprecateImages step type
Specify DeviceName for CreateInstances disks
Fix image resolution for DeprecateImage step
Add ListCallOption options to compute *ListCalls

Autobuilds

Add additional CLI tools to autobuild, drop the beta builds

Other

Initial commit of the gce_image_publish tool
Add gce_inventory_agent and instance_inventory

Workflows

Fix Cloud SDK install in EL6
Pull prebuilt gce_export instead of building in export workflows