Dhall for Kong declarative configuration

#1

Hi all,
Since v1.1.x, we can set up our Kong with the declarative configuration.
So, I have developed the configuration building API on dhall as the following.
https://github.com/RyanSiu1995/dhall-kong
The API follows the admin API to implement at the first stage. I have a plan on using the cross reference function in declarative configuration.
In case you guys have any suggestion on it, I am welcome on any kind of comment through github issue or pull request!
Thank you all!

Ryan