Tags

**New Features**

* Add `NodeTags` field to GCE CloudConfig. (#565)

**Bug Fixes**

* Null `ssh_authorized_keys` field is no longer rendered into cloud-init (#558)
* Before an eviciton is attempted, the machine-controller will now check if there is a possible target and if no, omit it. (#562)
* For Vsphere, ue the machine UID for identification instead of name. (#531)

Bug Fixes:

- Empty `image` and `flavor` are not allowed anymore for Openstack. (#532)
- GCE instances will now have public IP by default. (#533)

**Bug Fixes**:

- vSphere VMs are cleaned up on ISO failure. (#526)

**Enhancements**:

- It is now possible to configure the root disk size of vSphere machines. (#517)
- GCE instances can be configured to be multizone or regional. (#528)