Removed yargs dependency since it fails to install in windows

gulp/phantom.js

@@ -1,10 +1,12 @@
-var args = require('yargs').argv;
 // Switch to phantom.
 // Example:
 //    gulp --phantom
 
-var phantom = !!args.phantom;
-
-console.log('Phantom:', phantom);
+var phantom = false;
+process.argv.forEach(function (val, index, array) {
+  if(val=== '--phantom'){
+    phantom = true;
+  }
+});
 
 module.exports = phantom;