chore(prettier): fix syntax error in the rc file

Author: Kent C. Dodds

.prettierrc

@@ -4,7 +4,7 @@
   "useTabs": false,
   "semi": false,
   "singleQuote": true,
-  "trailingComma": 'all',
+  "trailingComma": "all",
   "bracketSpacing": false,
   "jsxBracketSameLine": false
 }