fix(package): update prettier to version 2.0.2

Closes #1127

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
     "normalize-path": "^2.1.1",
     "object.entries": "^1.0.4",
     "pdenodeify": "^0.1.0",
-    "prettier": "1.12.0",
+    "prettier": "2.0.2",
     "pump": "^3.0.0",
     "rollup-plugin-commonjs": "^9.3.4",
     "steal": "^2.2.0",