Hotfix for Kubernetes provider configuration issue

Pins the Terraform Kubernetes provider to 1.10 in order to workaround hashicorp/terraform-provider-kubernetes#759.

GKE deployer support

• Adds more outputs required by deployer
• Changes various instance type settings
• Refines variable inputs
• Adds kubeconfig generation

Production-ready changes

Adds changes to bucket lifecycle settings, opens cluster up for gcloud ssh access, and exposes more cluster metadata via outputs.

First bug fix

Updates underlying providers, test jobs and addresses issue with subsequent runs not being idempotent.

First stable release

Upgrade GCP: hope to fix NodePool delete error (#37)

* Upgrade GCP: hope to fix NodePool delete error

* Remove deprecated quoted references