Added configure property. Added configure test

lib/paypal-rest-sdk.js

@@ -64,7 +64,9 @@ module.exports = function () {
     }
 
     function configure(options) {
-        default_options = merge(default_options, options);
+        if (options !== undefined && typeof options === 'object') {
+            default_options = merge(default_options, options);
+        }
     }
 
     function generate_token(config, cb) {
@@ -338,6 +340,7 @@ module.exports = function () {
         configure: function (options) {
             configure(options);
         },
+        configuration: default_options,
         generate_token: function (config, cb) {
             generate_token(config, cb);
         },

test/configure-test.js

@@ -0,0 +1,15 @@
+"use strict";
+
+var chai = require('chai'),
+    expect = chai.expect,
+    should = chai.should();
+
+var paypal_sdk = require('../');
+require('./configure');
+
+describe('Configure Test', function () {
+    it ('Should return default options', function () {
+        var config = paypal_sdk.configuration;
+        config.should.be.a('object');
+    });
+});