honeycomb sampler: look at app.request.path
honeycomb sampler: look at app.request.path

OK. Last tweak on this (I hope).

`beeline.add_trace_field("request.path", ...)` apparently adds the
field as `app.request.path`, not just `request.path` (presumably to
avoid conflicts).

That means that for the sampler to actually see the spans associated
with `/heartbeat` requests, it has to look at that one as well if
`request.path` is missing (the root span will have `request.path` set,
child spans will have `app.request.path`).

appsembler/configuration,appsembler/configuration,appsembler/configuration,appsembler/configuration