added tests for global model options

spec/sequelize.spec.js

+var config    = require("./config/config")
+  , Sequelize = require("../index")
+
+describe('Sequelize', function() {
+  it('should pass the global options correctly', function() {
+    var sequelize = new Sequelize(config.database, config.username, config.password, {
+      logging: false,
+      define: { underscored:true }
+    })
+    var Model = sequelize.define('model', {name: Sequelize.STRING})
+    expect(Model.options.underscored).toBeTruthy()
+  })
+})