Define a consistent return value for each action

[SViccari]

The return values for each action vary for each class and vary for instance methods and class methods. This inconsistent behavior can be confusing to users and those interested in contributing to the library.

For example, depending on which class you're using, calling .update! or #update! will vary between returning a hash or an instance of the class.

How can we make this consistent and give our users the best experience?

[SViccari]

PR #171 proposes a way to make the response for all actions consistent and give users all the context that's provided by the HubSpot API response.