Update dependency prettier to v1.18.1

Author: renovate-bot

package.json

@@ -16,7 +16,7 @@
     "pwa-helpers": "0.9.1"
   },
   "devDependencies": {
-    "prettier": "1.16.4",
+    "prettier": "1.18.1",
     "rollup": "1.9.3",
     "rollup-plugin-node-resolve": "4.0.1"
   }

yarn.lock

@@ -57,10 +57,10 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/path-to-regexp/-/path-to-regexp-2.2.1.tgz#90b617025a16381a879bc82a38d4e8bdeb2bcf45"
   integrity sha512-gu9bD6Ta5bwGrrU8muHzVOBFFREpp2iRkVfhBJahwJ6p6Xw20SjT0MxLnwkjOibQmGSYhiUnf2FLe7k+jcFmGQ==
 
-prettier@1.16.4:
-  version "1.16.4"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.16.4.tgz#73e37e73e018ad2db9c76742e2647e21790c9717"
-  integrity sha512-ZzWuos7TI5CKUeQAtFd6Zhm2s6EpAD/ZLApIhsF9pRvRtM1RFo61dM/4MSRUA0SuLugA/zgrZD8m0BaY46Og7g==
+prettier@1.18.1:
+  version "1.18.1"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.18.1.tgz#2c79bdc97cbd457fc56e2f37c91cf076d69a8e07"
+  integrity sha512-cO2Lm9UuFJHhNgHSChbFddQEzNPP+sA6fX1tGmC0VNqTc2X+7EH0gpGWdEX0HfCe5+NVyOyyyWUpLKsb8LU5vg==
 
 [email protected]:
   version "0.9.1"