cbdr/ruby-cb-api — pull request #104 by jusroberts (2014-05-12 15:56:39+00:00)
Title: prototype around user.check_existing

Just putting this out there for people to look at.

To test the (possibly) new way of doing things, run this in pry:

```ruby
a = Cb::Client.new
a.make_call(Cb::Criteria::User::CheckExisting.new(email: "your_email", password: "your_password"))
```