Update dependency xo to v0.33.0

Author: renovate-bot

package.json

@@ -48,7 +48,7 @@
     "np": "6.4.0",
     "nyc": "15.1.0",
     "regenerator-runtime": "0.13.7",
-    "xo": "0.32.1"
+    "xo": "0.33.0"
   },
   "files": [
     "lib"