proxy from env support?

[saks]

Hi!
We found that simple_segment fails to connect to Segment API if HTTPS_PROXY env var is provided. It looks like the issue lies in the use of Net::HTTP.start method which accepts explicit proxy settings but does not favour env vars.

We've tried rewriting SimpleSegment::Request#post without method start and it seems works fine.

[whatthewhat]

Hey @saks!
I don't personally use proxies on the projects that use this gem, but looking at the docs it seems like Net::HTTP.start should be using the env variable as well 🤔

I'm not opposed to switching from Net::HTTP.start to something else, as long as there's no breaking change to http_options if you want to submit a PR.

btw, what ruby version are you running?

[saks]

Hey! Thanks for looking into it. You're right, it's a little change that was necessary to make Net::HTTP.start consider proxy settings from env vars.
We use 2.4.9, going to upgrade soon, but I don't expect any difference in the behaviour.

I've prepared a little PR to address it, please have a look.