chore(package): update documentation to version 12.1.0

Closes #13

Author: greenkeeper[bot]

package.json

@@ -25,7 +25,7 @@
   },
   "devDependencies": {
     "coveralls": "^3.0.0",
-    "documentation": "^7.0.0",
+    "documentation": "^12.1.0",
     "minimist": "^1.2.0",
     "nyc": "^12.0.1",
     "standard": "^11.0.1",