[KNIFE-417] knife-google compatible with GCE API v1

This version of knife-google is only compatible with GCE API v1.

* Images with an embedded kernel are now required to create a new instance with a persistent root disk. 
  * With GCE API v1, you cannot specify an image with a Google-provided kernel. Instead, you must provide an image with an embedded kernel and use it to create a root persistent disk before you can start an instance. When not explicitly specifying a boot disk name, the default boot disk name will be that of the instance. Persistent boot disk size must be between 10 and 10000 GB. When not explicitly specified, a 10 GB boot disk will be created.
* The option to create scratch boot disks has been removed. 
  * As part of the GCE transition to using persistent disks, scratch boot disks have been deprecated. It is not possible to create an instance in the v1 API with a scratch boot disk. 
* Removed the Kernels resource. 
  * With new support for embedded kernels, the Kernels resource is no longer required for launching an instance and has been removed completely from the v1 API. 
* When creating a new instance, it is now possible to specify instance scheduling options.
* Short options for non common knife plugin options have been removed.
* Options that were previously prefixed with `--google-compute` now begin with `--gce`
* User agent is now reported as knife-google/*gem-version-number*.
* All references to previous API versions have been updated.
* For more information please visit [https://developers.google.com/compute/docs/transition-v1](https://developers.google.com/compute/docs/transition-v1)