Switch build environment to Grunt

[bergie]

At the moment, Create is using the Cake task runner tool that ships with CoffeeScript for its build automation.

Switching to Grunt would enable us to provide more sophisticated build setups, and to leverage the existing work done in the Grunt plugin ecosystem.

For an example of the possibilities, see the NoFlo Grunt build config: https://github.com/bergie/noflo/blob/master/Gruntfile.coffee