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 is way too specific - this is going to vary a lot based on what length or allowed characters there are.  You might be better off calling this "secret" and generate a very long string of random characters (much longer than 8).  Also, remember that secret requirements vary greatly as well (Rails session cookie != Wordpress secret token).  I think you can probably just nuke this.