chore(package): update prettier to version 2.0.4

Closes #67

Author: greenkeeper[bot]

package.json

@@ -31,7 +31,7 @@
     "@types/jest": "^24.0.12",
     "@types/react-test-renderer": "^16.0.3",
     "jest": "^24.7.1",
-    "prettier": "^1.16.0",
+    "prettier": "^2.0.4",
     "react": "^16.8.0-alpha.1",
     "react-test-renderer": "^16.8.0-alpha.1",
     "ts-jest": "^24.0.2",