Remove `staging?` helper.
Remove `staging?` helper.

It was now incorrect with new chef setup and has
been refactored out of usage.
ahmadassaf/open-data-certificate,ahmadassaf/open-data-certificate,zoul/open-data-certificate,zoul/open-data-certificate,theodi/open-data-certificate,Motejl/open-data-certificate,istvan-antal/open-data-certificate,theodi/open-data-certificate,ahmadassaf/open-data-certificate,Motejl/open-data-certificate,istvan-antal/open-data-certificate,theodi/open-data-certificate,theodi/open-data-certificate,istvan-antal/open-data-certificate,zoul/open-data-certificate,ahmadassaf/open-data-certificate,Motejl/open-data-certificate,Motejl/open-data-certificate,zoul/open-data-certificate