add dependencies for per-file testing (#67)

Author: l3ender

test/addTarget.js

@@ -18,6 +18,7 @@
 var fullProject = require('./fixtures/full-project')
     fullProjectStr = JSON.stringify(fullProject),
     pbx = require('../lib/pbxProject'),
+    pbxFile = require('../lib/pbxFile'),
     proj = new pbx('.');
 
 function cleanHash() {