fix: rm vows dep

Author: piercus

package.json

@@ -32,7 +32,6 @@
   "devDependencies": {
     "ava": "^0.25.0",
     "semantic-release": "^15.1.7",
-    "vows": "^0.8.1",
     "winston": "^2.4.1",
     "xo": "^0.18.2"
   },