chore(package): update prettier to version 2.0.5

Closes #81

Author: greenkeeper[bot]

package.json

@@ -80,7 +80,7 @@
     "jest-vue-preprocessor": "^1.4.0",
     "lint-staged": "^7.0.0",
     "lodash": "^4.17.4",
-    "prettier": "^1.9.2",
+    "prettier": "^2.0.5",
     "rollup": "^0.58.2",
     "rollup-plugin-babel": "^3.0.3",
     "rollup-plugin-commonjs": "^9.0.0",