Add all ActiveRecord validations and callbacks to `RecordSpy`

This adds all of ActiveRecord's validations and callbacks to the
`RecordSpy`. This probably should've been done earlier, instead
of adding them as needed, but this should cover what ActiveRecord
currently provides.

@kellyredding - Should of gone ahead and done this. After I rolled the current version I found a case where I needed `after_destroy`, so I decided I should just add them all so I don't have to keep rolling versions.