split queue time and queue depth into different middlewares
request id for request metrics
extract Rails AS::Notify stuff into a module for both middlewares
add diff + cleanup queue_time
iterate
round dyno_start
add app time metrics
capture time spent in middleware stack
rename dyno_start to middleware_start
report the address when using queue depth
use stdlib logger instead of hardcoding to
notify request_start_delta
notify middleware_delta and app_delta