Add PhantomJS dev dependency (#87)

Author: svbergerem

package.json

@@ -58,6 +58,7 @@
     "karma-safari-launcher": "^0.1.1",
     "mocha": "^2.3.3",
     "node-static": "^0.7.7",
+    "phantomjs": "^2.1.7",
     "semver": "^5.0.3",
     "underscore": "^1.6.0",
     "yiewd": "^0.6.0"