Setting RACK_ENV in config.ru doesn't serve any use case I know of.

When using rackup, use the -E option. When using thin or puma or passenger, use
-e option. When using Passenger with Apache, it will automatically be set to
'production'.

None of the above works for you? export RACK_ENV yourself. Consider doing this
in a startup script.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>