{
  "repository": {},
  "license": "MIT",
  "scripts": {
    "deploy": "brunch build --production",
    "watch": "brunch watch --stdin"
  },
  "dependencies": {
    "phoenix": "file:../deps/phoenix",
    "phoenix_html": "file:../deps/phoenix_html"
  },
  "devDependencies": {
    "babel-brunch": "6.0.6",
    "brunch": "2.10.7",
    "clean-css-brunch": "2.10.0",
    "sass-brunch": "^2",
    "uglify-js-brunch": "2.1.1",
    "bootstrap": "4.0.0-alpha.6"
  }
}

{
  "repository": {},
  "license": "MIT",
  "scripts": {
    "deploy": "brunch build --production",
    "watch": "brunch watch --stdin"
  },
  "dependencies": {
    "bootstrap": "^4.0.0-alpha.6",
    "phoenix": "file:../deps/phoenix",
    "phoenix_html": "file:../deps/phoenix_html"
  },
  "devDependencies": {
    "babel-brunch": "6.0.6",
    "brunch": "2.10.7",
    "clean-css-brunch": "2.10.0",
    "sass-brunch": "^2",
    "uglify-js-brunch": "2.1.1"
  }
}

Move bootstrap to dependencies section
Move bootstrap to dependencies section