if run in an addon it puts styles in app folder instead of addon

[BryanCrotaz]

When the generator is run in an addon folder the scss files should go in addon/, not app/ And pods.scss should be in addon/styles

And docs should read

Watched folder Add paths for watching in the 'ember.cli-build.js':

var app = new EmberApp(defaults, {
  sassOptions: {
    includePaths: ['app', 'addon']
  }
});