message: Move `@types/styled-systems` back to production dependenies
diff: "polished": "3.5.2",
  "react": "^16.10.2",
  "react-is": "16.10.2",
  - "styled-system": "5.1.2"
  + "styled-system": "5.1.2",
  + "@types/styled-system": "5.1.2"
  },
  "devDependencies": {
  "@testing-library/react": "9.4.0",
  "@types/styled-components": "^4.4.0",
  - "@types/styled-system": "5.1.2",
  "@babel/cli": "7.8.4",
  "@babel/core": "7.9.0",
  "@babel/plugin-proposal-nullish-coalescing-operator": "7.12.1",
  