[nginx] increase number of running timers

[nginx] increase default pool size for sockets

that returns information about timers

doing synchronous call in the post_action will
push the latency to the client on the same connection

using timers we can make that fully asynchronous
not being tied to the request phase at all

setting APICAST_REPORTING_THREADS environment variable
to a number greater than 0 will enable reporting in asynchronous
timers instead of synchronous call

the number defines a maximum number of parallel calls
to backend per worker

if there is new report coming but no connections is available
APIcast will wait for up to 10 seconds before falling back to the
synchronous call

please note this is **experimental** feature

so SSL validation will work

$ openssl ecparam -genkey -name prime256v1 -out key.pem
$ openssl req -new -sha256 -key key.pem -out csr.csr -subj '/CN=127.0.0.1'
$ openssl req -x509 -sha256 -days 3650 -key key.pem -in csr.csr -out certificate.pem

because tests run in the same context