Pass Hackney options from config

[marcinbiegun]

I've run into problems with timeouts (>5 seconds) coming from our Stripe test account.

The only piece of documentation regarding timeouts is here https://hexdocs.pm/stripity_stripe/Stripe.html#module-http-connection-pool But it doesn't change for how long the library waits for the server's response.

This change allows to set that timeout as additional opts for the Hackney HTTP client.

[coveralls]

Coverage increased (+0.9%) to 87.241% when pulling 0e4c213 on marcinbiegun:hackney-opts-from-config into 43e3a39 on code-corps:master.

[snewcomer]

So while we are considering the best option, I just wanted to make sure that passing recv_timeout as the opts argument to any method will bump the time the http response time. If this is true, we probably want to document and let users know that if they want to do it on a per request basis, they can do so.

https://github.com/benoitc/hackney/blob/master/doc/hackney.md

[tylerwray]

Any idea when this will get into a release? We're running into this problem quite a bit.

[snewcomer]

@tylerwray v2.5.0!