Update README.md to document thread safety
add ruby 2.0 to .travis.yml
Regular expression fix

In Ruby, `^` and `$` match the line beginning and line end. So, an email
coming in via HTTP like this:

    user@example.com%0A<script>alert('hello')</script>

Whereas %0A is a line feed in URL encoding, so Rails automatically
converts it to:

    user@example.com\n<script>alert('hello')</script>

and unintentionally passes validation because the regular expression
matched the email: up to the line end, the rest does not matter.

http://guides.rubyonrails.org/security.html#regular-expressions
Merge pull request #8 from croaky/regular-expression-fix

Regular expression fix
release 1.4.0
remove Gemfile.lock; cleanup gemspec file; use HTTPS for Rubygem source
remove rdoc tasks from Rakefile
Fixed false positives if email contains linebreaks