chore(package): update yeoman-test to version 1.6.0

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -84,7 +84,7 @@
     "shelljs": "^0.7.5",
     "should": "^11.1.0",
     "yeoman-assert": "^2.0.0",
-    "yeoman-test": "~1.5.0"
+    "yeoman-test": "~1.6.0"
   },
   "engines": {
     "node": "^6.2.2",