When verify is false in the faraday adapter, turn off peer verification.

I was having an issue with faraday requests entering a black hole when using self-signed certs and typhoeus as the adapter. After having a poke inside I found the ssl_verifypeer request option wasn't being set to false when the verify ssl option was set to false. The default for this curl option is true[1]. 

This PR changes the faraday adapter to turn off peer verification when verify is set to false.

[1] - http://curl.haxx.se/libcurl/c/curl_easy_setopt.html#CURLOPTSSLVERIFYPEER