Fixing jslint errors

Author: bdenham

src/guides/v2.3/performance-best-practices/samples/build.js

@@ -501,4 +501,4 @@
       ]
     }
   ]
-})
+})()

src/guides/v2.3/performance-best-practices/samples/deps.js

@@ -1,6 +1,8 @@
 'use strict'
 const page = require('webpage').create()
 const system = require('system')
+const phantom = require('phantomjs')
+
 let address
 if (system.args.length === 1) {
   console.log('Usage: $phantomjs deps.js url')