chore(package): update @types/prettier to version 1.18.3

Closes #34

Author: greenkeeper[bot]

package.json

@@ -98,7 +98,7 @@
     "@types/jest": "24.0.12",
     "@types/json5": "0.0.30",
     "@types/node": "11.13.8",
-    "@types/prettier": "1.16.3",
+    "@types/prettier": "1.18.3",
     "@types/webpack-config-utils": "2.3.0",
     "awesome-typescript-loader": "5.2.1",
     "chalk": "2.4.2",