Some of the API services are not properly mounted under /$service/
in the apache proxy. This patch tries to avoid recording data
for "services" like "v2.0" (in the case of neutron) by only adding
names if they're all letters. A single warning is emitted for any
services excluded by this check.
For the moment this will mean we don't collect data for those services,
but when their devstack API config is fixed, they'll start to show
up.
Change-Id: I41cc300e89a4f97a008a8ba97c91f0980f9b9c3f