chore(package): update prettier to version 1.15.0

Author: greenkeeper[bot]

package.json

@@ -37,7 +37,7 @@
     "laravel-mix": "^2.1.14",
     "offline-plugin": "^5.0.5",
     "pre-commit": "^1.2.2",
-    "prettier": "1.14.3",
+    "prettier": "1.15.0",
     "stylelint": "^9.7.1",
     "stylelint-config-sass-guidelines": "^5.2.0",
     "stylelint-scss": "^3.3.2"