replace usage of pooler by inaka worker_pool
fix async request
add request/7 request/8, async_requesy/7

Allows to pass the strategy and timeout to request and strategy to cast.
start missing inets

fix warning
number of workers is set differently
also use the number of workers here too
fix env configuration example
idna is already included in hackney
fix async_request function
since worker_pool include it, just use lager
Merge pull request #1 from benoitc/worker_pooler

replace usage of pooler by inaka worker_pool