edit events

created the option to edit posted events by:
*Adding an edit button to each posted event by current_user
*creating a view to edit details
*having the events_controller update events and redirect back to
dashboard
Partials shouldn't have instance variables. Are you using this form for anything other than events? If not, the path should be `events/_form.html.erb`. That way `@event` is implied and you can just use `event`.