Update for Optify's v2 API

[stim371]

Optify has released their v2 api with additional endpoints and actions available.

http://www.optify.net/product-news/new-api-for-digital-marketing-software

Ideas for the new version:

• Bump major version due to breaking changes
• Allow user to specify api version in initializer
  • default to v2 api
  • See bitly gem for how they allow users to go back to old system
  • move code into an Optify::API::V1 module so you can include one or the other
• Gather all the new functions/endpoints and decide if they can all be put into the same spot.

What else am I missing?