html5_validator gem

Gem used: https://github.com/damian/html5_validator

**MAJOR ISSUE: only works with an internet connection => will be real slow when validating everything!!**

Also, this didn't work out of the box as the `gemspec` dependencies pointed to fixed and quote old versions. :-1:
Output:

```
  1) Valid HTML5 Member is not signed up I do not exist as a member -> I sign in with valid username and password -> I see an invalid login message -> I should be signed out -> the page should be valid HTML5
     Screenshot: /Users/josh/Documents/Work/MuheimWebdesign/transition/tmp/capybara/screenshot_2014-01-02-22-40-19.158.png
     Failure/Error: And the page should be valid HTML5
     SocketError:
       getaddrinfo: nodename nor servname provided, or not known
     # /Users/josh/Documents/Work/MuheimWebdesign/html5_validator/lib/html5_validator/validator.rb:16:in `validate_text'
     # /Users/josh/Documents/Work/MuheimWebdesign/html5_validator/lib/html5_validator/matchers.rb:8:in `block (2 levels) in <top (required)>'
     # ./spec/support/steps/global_steps.rb:6:in `block in <top (required)>'
     # ./spec/acceptance/members/valid_html.feature:9:in `the page should be valid HTML5'
```