Kubernetes 1.6 adds a `PpropagationPolicy` to the delete options,
obsoleting the previous `OrphanDependents` boolean.

This change sets `PropagationPolicy=foreground`, keeping the legacy
`OrphanDependents=false` for older k8s servers.

Note that PropagationPolicy=background is broken in k8s 1.6 and (eg)
leaks pods from a deployment.  See kubernetes/kubernetes#44046 for
upstream discussion.

Add 'subset' diff stategy option that checks the live state is a subset of the config state.

Anonymously import the GCP auth provider to get the registration side effect.

Register *all* auth plugins (gcp + oidc)

Fix deploy runtime version check harder

Travis' deploy.on golang version check seems to be surprising.  In
particular `deploy.on.go=1.8.x` will *not* match a build performed
with `go=['1.8.x']`.

This change just gives up and uses an explicit bash conditional.
Uglier, but fewer surprises.

Update to newer xcode for travis osx builds

Frequent `make test` crashes on (default) xcode7.3 in jsonnet_cgo. Use
a different/newer build environment.

Fix go point-release version references

Prefer `1.8.x` rather than `1.8`.  In particular `deploy.on.go=1.8` does
not match (eg) `1.8.3` :(

Update to client-go release-3

Switch logging from glog to logrus

Add per-file license headers

Improve interactive output experience by switching to a logging
library (logrus) that allows customising the output format.

This also removes the glog command line flags.  Replaced with a
simpler `--verbose`/`-v` option:
- quiet by default (warnings and errors only)
- `-v` for progress info
- `-vv` for debug

Fixes #34

Fixes #35

More complete implementation of extvars, topvars

Fix goreportcard-reported lint issues

- `gofmt -s utils/registry_test.go`
- Fix missing `if err != nil` check in `cmd/delete.go` (a bug, but not critical)
- Add goreportcard button to README

Replace quickstart example with something that works

Add several regex native functions

Rename --extVar to --ext-str

- `escapeStringRegex`
- `regexMatch`
- `regexSubst`

They do what you expect, as implemented by the golang `regexp` package.

For consistency with other options (hyphenated, not camel case), and
the upstream `jsonnet` tool.

This allows you to actually reach the guestbook in most environments
without further changes (including minikube, since LoadBalancer
implies NodePort).

Remove poor attempt at setup step entirely.  This makes the actual
quickstart content more obvious ... and anyone who _actually_ wants to
run it will already know how to checkout a git repo.

Update jsonnet-cgo to 04f8990