Copy files to zoo4.galaxyzoo.org when deploying
Copy files to zoo4.galaxyzoo.org when deploying

So we have a permanent archive of the site after future versions are
launched.

Closes willettk/gzhubble#74

zooniverse/Galaxy-Zoo,alexbfree/Galaxy-Zoo,murraycu/Galaxy-Zoo,murraycu/Galaxy-Zoo,zooniverse/Galaxy-Zoo,alexbfree/Galaxy-Zoo,willettk/Galaxy-Zoo,willettk/Galaxy-Zoo,zooniverse/Galaxy-Zoo,murraycu/Galaxy-Zoo,alexbfree/Galaxy-Zoo,willettk/Galaxy-Zoo