chore(package): update prettier to version 2.0.3

Closes #61

Author: greenkeeper[bot]

package.json

@@ -64,7 +64,7 @@
     "husky": "^3.0.9",
     "jest": "^24.9.0",
     "lint-staged": "^9.4.2",
-    "prettier": "^1.18.2",
+    "prettier": "^2.0.3",
     "rimraf": "^2.7.1",
     "style-loader": "^1.0.0",
     "stylelint": "^11.1.1",