Issue setting up ionic sass

My project has the following in it's package.json

  "dependencies": {
    "async": "^1.4.0",
    "bower": "^1.3.3",
    "gulp": "^3.5.6",
    "gulp-angular-templatecache": "^1.5.0",
    "gulp-sass": "2.3.2",
    "gulp-sourcemaps": "^1.5.2",
    "gulp-util": "^2.2.14",
    "require-dir": "^0.3.0",
    "shelljs": "^0.3.0"
  },

And I've run the following commands

npm update

npm install

npm install gulp-sass

However, no matter what I do, when I run the following command

ionic setup sass

I am given the following error:

D:\development\ionic_starter_project>ionic setup sass
[ERROR] Unable to find command: setup sass

via PSU_Kardi