Use Consistent Method Names

[sshaw]

Some methods uses snake_case and others use camelCase. Everything should use camel_case, as this is the Ruby convention.

Additionally, since you're using Hashie, one will never know that they're calling the wrong method. For example, your README uses posting.created_at but it's really posting.createdAt. Since you're using Hashie, no NoMethodError is returned. Instead
it returns nil.