Make a generator for a custom coffeelint.json

[kimroen]

We have instructions in the readme and an example of how a custom coffeelint.json could look. The rule in there about allowing backticks is pretty much mandatory, so it would be nice if the user could type something like ember g coffeelint and get one.

Should be pretty straightforward - add a new blueprint to the /blueprints-folder with that name and a nice description.

We could expand upon this and ask about it when the user installs ember-cli-coffeescript, as discussed in #65

[kimroen]

This coffeelint-rule isn't as mandatory as it once was now that CoffeeScript supports import and export directly.

I don't think adding this generator is worth doing.