Update openstack testing workflow

Openstack use berkshelf 3 and `berks install --path` don't working anymore, use `berks vendor` instead.
Strainer is no longer used and a Rakefile have been added to make the job, the default command for testing lint, style and unit is `bundle exec rake`.
edits, apply swap names
move URL_or_URI to options (it's optional!)
hook in options
add context
update strings for correct Knife values
edits
change example title; hook in new example
edits
apply change to release notes too!
add swaps, hook them in
fix titles
Merge pull request #423 from PierreRambaud/patch-1

Update openstack testing workflow
update download options
update options for upload
update --org-name
add azure_portal to windows.html
rebuild page, redirect, then re-archive
edits, sync, hook in
sync intro, add to server_security topic