Added schema for a com.mailchimp/campaign_sending_status event (closes #52)
Added schema for a com.mailchimp/cleaned_email event (closes #51)
Added schema for a com.mailchimp/email_address_change event (closes #50)
Added schema for a com.mailchimp/profile_update event (closes #49)
Added schema for a com.mailchimp/subscribe event (closes #47)
Added schema for a com.mailchimp/unsubscribe event (closes #48)