introduce Folder#copy_to
refactor Folder#copy_to
add a link to the api documentation for Folder#copy_to
expect -> should synax
Merge pull request #79 from leviwilson/folder-copy_to

Added Folder#copy_to method thanks for the thorough tests!
rolling version #.
updating gemspec.
Add opts param to session#authroize_url to enable CSRF protection.
Use different method instead of opts for state param.
#83 - return result of recursion if retry with refresh
updated version #.
Merge pull request #86 from attachmentsme/refresh

Merge of #83, Return Result After Refresh
Use optional state param.
Cleanup session spec.
Merge branch 'state-param' of github.com:skalb/ruby-box into state-param
minor edits to spec.
Merge pull request #87 from attachmentsme/state-param

Add authorize_url_with_state to allow for CSRF protection.