TemplateConfig implementation with Kubernetes

Initial implementation of TemplateConfig REST endpoint.

See the project.json example.

To test this PR:

```
$ curl -d @pkg/template/examples/project.json \
  http://localhost:8080/api/v1beta1/templateConfigs
```

This will return `Config{}` which is essentially the same as a `templateConfig{}` but without parameters.

**FYI**: This is a wip, all commits will be squashed in the end. @VojtechVitek is working on validation atm. so I don't want to force push ;-)
this Bar is a Foo AND this is what its implementation of Foo does.  Otherwise, there's not much point to the interface if your object is so concrete there can be only one implementation.  We're ratholing a bit - I wanted to see the GoDoc of structs in general describe why they exist and what they do - what interface they implement is only the first part.