add Gemfile for bundler
fix broken test
add support for proxies to Net::Ping::HTTP

It now inspects the http_proxy, https_proxy and no_proxy environment variables and behaves accordingly.
use gemspec for bundler
one more tweak to Gemfile
remove comments from tests
set an attribute to indicate if a ping request was proxied
Merge pull request #15 from 6fusion/master

add support for proxies to Net::Ping::HTTP