Gem setup and add CI and READMEs

Gem version 0.0.1
Jenkins script to run rspec and publish gem on success
Travis build for all branches
Changelog and README
Rakefile with tasks to run tests and publish gem
Adjust Gemfile to use gemspec
Merge pull request #2 from alphagov/ci-setup

Gem setup and add CI and READMEs
Add a README.md