Add support for URI Template

@rprieto @nguyenchr 
do we need to pass in config.templateValues?
I might be missing something but it looks like the only place that uses the template values is this function

e.g it could just be 
```coffee
expandUrl = (url) ->
  values = config.templateValues
  if _.isObject(values) and not _.isEmpty(values)
    templates(url).fillFromObject(values)
  else
    url
```