Kubetools

This release follows a major overhaul of Kubetools - most notably moving all of the server/build logic down into this library (to deprecate/remove the server). The `kubetools` command can now deploy direct to Kubernetes.

- **Migration to client-only** (no more server), meaning new/changed commands:
+ `kubetools deploy <namespace> <app_path> [<app_path>...]`
+ `kubetools remove <namespace> [<app>...]`
+ `kubetools restart <namespace> <app>`
+ `kubeotols cleanup <namespace>`
+ `kubetools show <namespace> [<app>]`
+ Commands removed:
* `kubetools wait`
* `kubetools list *`
* `kubetools job *`
- **Remove Python 2 support**
- Uses `kubeconfig` and Kubernetes contexts
- Correctly uses Kubernetes deployment objects for proper rolling updates
+ This also adds rollback compatability
- Improved replica control in `kubetools.yml`:
+ `deployments.NAME.minReplicas` (max exists already)
+ `deployments.NAME.replicaMultiplier`
- Support deployment strategy in `kubetools.yml`:
+ `deployments.NAME.updateStrategy` -> K8s `Deployment.spec.strategy`
- Add `--annotation` argument to `kubetools deploy`
- Add `--shell` argument to `ktd enter`

- Always ensure deployment names start with the project name

- Fix Python 2 compatability (broken in v10)

- Add `KTD_ENV` environment variable in `docker-compose` dev backend
- Print out all injected environment variables in `docker-compose` dev backend
- Replace `envars` with `envvars` everywhere (w/backwards compatability)

- Fix issue where stdout from a kubetools dev exception would not be formatted properly
- Add "dev backends" support for future work (alternatives to `docker-compose`)
- Add kubernetes config generation from the kubetools server
* adds `kubetools configs` command to generate/view them by hand

- Add ability to define number of retries on readinessProbe