* before running tests

This commit adds a target called setup-gotools which will download and
install golint and go vet. A developer who wants to run tests for an
individual component (manager, resourcifier, expandybird) can run `make
test` to run golint, vet, and test and in that directory. On first run,
a developer will want to run `make setup-gotools` so that they have
golint and vet to use locally.

There is a `make test` command in each component because running tests
from the root directory will result in lots of output. Running tests in
individual components will help isolate the tests for the component that
is being modified and result in more clear output.

add structure for [lint,vet,test-unit] all wrapped up
by the test target

Add ObjectStorage (and GCS implementation) as a registry provider

Add GCS as a registry provider. Add a way to get a file using credentials from a registry to support private repos. Add ability to create / update a registry through manager

add info target in makefiles

add health check to resourcifier

dm: cleanup CLI UX for people getting started

Fixed Dockerfile bugs.

pass err to Fatalf

fix typo

fix struct tag

fix string formatting verb

fix string formatting typo

add health check

Now when `--help` is called we get all of the subcommands listed too.

Before this patch dm would print out the wall of usage text that would
scroll off the screen in many error cases. This made learning dm hard.
Instead have more compact error output, like kubectl, and only return
non-zero on real errors.

```
$ dm foo ; echo $?
Error: unknown command 'foo' for 'dm'
Run 'dm --help' for usage
1
$ dm deployed-instances; echo $?
No type name supplied
1
$ dm 2> /dev/null; echo $?
0
```

There is more to do to make this tool friendlier but this was
low-hanging.

This commit adds a liveness probe to the manager rc and
a healthz endpoint that returns 200 OK.

Use the actual kubernetes object when deleting to ensure it absolutely

Have configurator use the kubernetes_kubectl object

Wire [gs]etcredential to backend

Preserve environment variables executing expansion

Running tests locally fail because $PATH is destroyed

Add support for k8s secrets backed credentials