In an earlier cleanup (commit b1663a23c), a number of settings.DEBUG

checks were turned into not settings.PRODUCTION. However, the one in

the Root Resource that forced an error when duplicate URI templates key

were found was changed to not settings.DEBUG. This would have broken

production installs but largely gone unnoticed in development installs.
We never want to trigger this during production, but it may be nice to

be able to trigger this in a development environment with DEBUG=False.

So I've updated the check to only raise an exception when in developer

mode with DEBUG=False, and otherwise simply log.

Unit tests pass.