Add updates notes the changelog, update Gemfile.lock

Before we can Ship version 3.2.5, as in (https://github.com/Shopify/shopify_api/pull/140), we need to: 
* Update the Gemfile.lock with the new version
* Add the changes in our change log.

Note: Current deploy is failing since it is looking for version 3.2.3 in the `Gemfile.lock.`

@pickle27 @csaunders Please review.