message: install chroma-js, move style-system from devDependencies
diff: },
  "dependencies": {
  "@githubprimer/octicons-react": "8.0.0",
  + "chroma-js": "1.3.7",
  "classnames": "^2.2.5",
  "d3-shape": "^1.2.0",
  "emotion": "9.2.6",
  "react": "^16.2.0",
  "react-emotion": "9.2.6",
  "system-classnames": "^1.0.0-3",
  - "system-components": "3.0.0"
  + "system-components": "3.0.0",
  + "styled-system": "2.3.6"
  },
  "devDependencies": {
  "@compositor/kit": "^1.0.43",
  "rollup": "0.62.0",
  "rollup-plugin-babel": "3.0.5",
  "rollup-plugin-commonjs": "9.1.3",
  - "styled-components": "3.3.3",
  - "styled-system": "2.3.6"
  + "styled-components": "3.3.3"
  }
  }
  