The bug report templates are now executed from the `ci/travis.rb` when
`GEM` contains `guides`.
I started by creating a `test` task in `guides/Rakefile` to handle this,
but since inline `gemfile` must not be executed with `bundle exec`, that
rake task would not be consistent with others. So I went back by
executing them directly from `Build`.
Use inline Gemfile dependency when reporting gem bugs
