Remove Guest#initialize_with_name_and_email

* Remove Guest#initialize_with_name_and_email
* Remove Guest#set_has_ever_logged_in (replaced with update_attributes)
* Break long lines
* Shorten Guest specs to use FactoryGirl.create instead of save!
* Refactor Guest specs to test Guest.find_or_initialize_by_email (probably unnecessary since this is a core method)