Update prettier to version 1.9.2 (#184)

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "nyc": "^11.0.2",
     "per-env": "^1.0.2",
     "postcss-import": "^11.0.0",
-    "prettier": "1.9.1",
+    "prettier": "1.9.2",
     "standard": "^10.0.2",
     "sugarss": "^1.0.0",
     "uuid": "^3.0.1"