Ignore any non-HTTP(S) URI

Fixes https://github.com/gjtorikian/html-proofer/issues/119
Merge pull request #120 from gjtorikian/ignore-protocols

Ignore any non-HTTP(S) URI
use addressable
add test for non-standard links
passing-ish tests
Reference a version file in the gemspec
Add html/proofer/version.rb

So this can be required independently.
Require html/proofer/version.rb inside html/proofer.rb
Simplify "no redirects" test
Merge pull request #122 from benbalter/addressable

Better URL parsing through science
Merge pull request #127 from gjtorikian/fix-dang-old-test

Simplify "no redirects" test
Remove crazy extra comma.
HTML is a module.
Merge pull request #123 from parkr/patch-1

Add a version file
Added an html validation check by looking at Nokogiri errors
Merge pull request #125 from akoeplinger/html-validation

Added an html validation check by looking at Nokogiri errors
Merge master