chore(package): update prettier to version 1.8.1

Closes #1848

Author: greenkeeper[bot]

package.json

@@ -118,7 +118,7 @@
     "marked": "0.3.6",
     "minimist": "1.2.0",
     "pify": "3.0.0",
-    "prettier": "1.7.4",
+    "prettier": "1.8.1",
     "prop-types": "15.6.0",
     "react-native-view-shot": "1.12.0",
     "react-test-renderer": "16.0.0-alpha.12",