chore(package): update eslint-config-xo to version 0.22.1

Closes #34

Author: greenkeeper[bot]

package.json

@@ -25,7 +25,7 @@
     "babel-preset-es2015-rollup": "^3.0.0",
     "coveralls": "^3.0.0",
     "eslint": "^4.0.0",
-    "eslint-config-xo": "0.19.0",
+    "eslint-config-xo": "0.22.1",
     "jest-cli": "21.2.1",
     "rollup": "^0.53.0",
     "rollup-plugin-babel": "^3.0.2",