refactor(extended-json): use mongodb-extjson in corpus tests

Author: mbroadst

Diff for: package.json

@@ -23,6 +23,7 @@
     "nan": "^2.9.2"
   },
   "devDependencies": {
+    "mongodb-extjson": "^2.1.0",
     "nodeunit": "~0.9.0"
   },
   "main": "./index",

Diff for: test/node/bson_corpus_tests.js

@@ -1,8 +1,9 @@
 var BSON = require('../..'),
   Decimal128 = BSON.Decimal128,
   Long = BSON.Long,
-  deserialize = require('../../extended-json').deserialize,
-  serialize = require('../../extended-json').serialize,
+  EJSON = require('mongodb-extjson'),
+  deserialize = EJSON.parse,
+  serialize = EJSON.stringify,
   f = require('util').format,
   assert = require('assert'),
   fs = require('fs');