chore(package): update size-limit to version 2.1.6

Closes #22

Author: greenkeeper[bot]

package.json

@@ -43,7 +43,7 @@
     "eslint": "^4.18.0",
     "mocha": "^5.2.0",
     "nyc": "^12.0.2",
-    "size-limit": "^1.0.1"
+    "size-limit": "^2.1.6"
   },
   "repository": {
     "type": "git",