chore(package): update prettier to version 2.0.4

Closes #166

Author: greenkeeper[bot]

package.json

@@ -69,7 +69,7 @@
     "html-webpack-plugin": "3.2.0",
     "jest": "^24.9.0",
     "jest-styled-components": "^6.3.3",
-    "prettier": "^1.17.1",
+    "prettier": "^2.0.4",
     "react-test-renderer": "16.8.6",
     "redux-mock-store": "1.5.4",
     "storybook-addon-styled-component-theme": "1.2.5",