Honor Host header when connecting to IPs

[moorereason]

Fixes #36

[davecheney]

I wonder if this is a bridge too far, the feature is quite esoteric, and its usage is even more so. I'm leaning towards saying No to this one.

[moorereason]

Let's try this again after getting some sleep. 😉

[theckman]

@davecheney at work I'm often doing testing against singular IPs, while passing in a Host header:

curl -IH 'Host: blah.work.tld' http://<TEST_IP>/

I'd replace my usage with httpstat if it supported it.

[theckman]

Can we make this a bit more resistant to failure? If Google ever adds multiple A records this test will fail. How do you feel about dig +short www.google.com | head -n 1?

[moorereason]

Good idea, but it turns how that I can't use dig in Travis anyway. If anyone has any better ideas, let me know. Pushed a hard-coded test for now.

[theckman]

Oh, nevermind...

$ {:"./httpstat -H \"Host"=>"www.google.com\" https://$(dig +short www.google.com):443/"}
/home/travis/build.sh: line 45: dig: command not found
/home/travis/build.sh: line 45: dig: command not found
/home/travis/build.sh: line 45: www.google.com" https://:443/}: No such file or directory

😂

[theckman]

@moorereason maybe we can add this to the top of the .travis.yml file:

addons:
  apt:
    packages:
    - dnsutils

You should then have dig.

[theckman]

I think I'd prefer to use dig over the hard-coded IPv4 address. However, I don't feel strongly enough to block it (easy enough to open a separate PR to enhance the Travis testing).

[moorereason]

@theckman, thanks for the addons info. Fixed. 👍