Add TravisCI config

In preperation for enabling TravisCI to run lint and unit tests against our
pull requests. This:

- Uses the Ruby defaults such as `bundle install` and `bundle exec rake`.
- Only tests 1.9.3 at the moment, which I think is what we're targetting?
  But we might want to extend it to 2.x in the future.
- Doesn't test against master because that is handled by our in-house CI
  system which also runs integration tests.
- Disables email notifications because we already get a lot of email and the
  PR status hook on GitHub should be good enough.
Move examples into folder named after command

Move the example YAML files into a folder named after the command that
they are used for, in this case 'vcloud-configure-edge'.

This is for consistency with the other vCloud Tools[1][2].

[1]: https://github.com/alphagov/vcloud-launcher/tree/master/examples
[2]:
https://github.com/alphagov/vcloud-net_launcher/tree/master/examples
Merge pull request #54 from alphagov/70499778-add_travis_config

[#70499778 ] Add TravisCI config
Merge pull request #55 from alphagov/move-examples

Move examples into folder named after command
Document how to use templating

Example CLI usage and configuration files.