Prometheus::Tiny is a minimal metrics client for the Prometheus
time-series database.

It does the following things differently to Net::Prometheus:

 - No setup. You don't need to pre-declare metrics to get something useful.
 - Labels are passed in a hash. Positional parameters get awkward.
 - No inbuilt collectors, PSGI apps, etc. Just the metrics.
 - Doesn't know anything about different metric types. You get what you ask for.

These could all be pros or cons, depending on what you need. For me,
I needed a compact base that I could back on a shared memory region.
See Prometheus::Tiny::Shared for that!
