Add grunt-cli to help Travis execute tasks

Author: zenorocha

package.json

@@ -7,6 +7,7 @@
 	"version": "0.2.7",
 	"devDependencies": {
     "grunt": "~0.4.1",
+    "grunt-cli": "~0.1.7",
     "grunt-contrib-jshint": "~0.4.3",
     "grunt-contrib-concat": "~0.3.0",
     "grunt-contrib-uglify": "~0.2.0"