Sendgrid-nodejs: require(...).SendGrid is not a function

Issue Summary

_Using v3 Mail for Node.js._

In your documentation for v3 Mail, under "Node.js" code examples, you specify on _line 11_, to write

var sg = require('sendgrid').SendGrid(process.env.SENDGRID_API_KEY)

however, when I do, i receive TypeError: require(...).SendGrid is not a function with a pointer ^ (carat) at the period between ) and SendGrid(process.env.SENDGRID_API_KEY).

However, when I do this...

const sendGrid = require('sendgrid')(process.env.SENDGRID_API_KEY); //removing the .SendGrid method
console.log('sendGrid: ', sendGrid);

I receive NO error's and I can successfully send an email.

Please let me know if I have missed something, however, if I have not, you may consider updating your documentation to remove future confusion.

P.S.

SendGrid is awesome. Keep doin' good work.
-Tobiah Rex

• sendgrid-nodejs Version: master (latest commit: 0df1613)
• Node.js Version: 6.2.1