COOK-2330: use String#upcase in celeryconfig.py.erb
COOK-2330: use String#upcase in celeryconfig.py.erb

I'm not sure how (or if) this ever worked before, as String#upper
doesn't seem to be a valid method.

chenliu0831/application_python,janusnic/application_python,janusnic/application_python,noradaiko/application_python,zpallin/application_python,eevol/application_python,poise/application_python,h4ck3rm1k3/application_python,LiamK/application_python,LiamK/application_python,noradaiko/application_python,needle-cookbooks/application_python,javrasya/application_python,chenliu0831/application_python,needle-cookbooks/application_python,h4ck3rm1k3/application_python,eevol/application_python,poise/application_python,zpallin/application_python,javrasya/application_python