fix(package): update joi to version 14.1.1

Closes #38

Author: greenkeeper[bot]

package.json

@@ -11,7 +11,7 @@
     "es6bindall": "^0.0.9",
     "filewrap": "^1.0.0",
     "glob": "^7.1.2",
-    "joi": "^13.0.2",
+    "joi": "^14.1.1",
     "js-yaml": "^3.9.1",
     "lodash.bindall": "^4.4.0",
     "markdown-it": "^8.3.2",