Help jasmine tests run
Help jasmine tests run

This was repeatedly failing in CI with the error:

```
[build] [2018-03-28 17:00:49] ERROR Sprockets::Rails::Helper::AssetNotPrecompiled: Asset was not declared to be precompiled in production.\nAdd `Rails.application.config.assets.precompile += %w( all.js )` to `config/initializers/assets.rb` and restart your server
[build]   /var/lib/jenkins/bundles/ruby/2.4.0/gems/sprockets-rails-3.2.1/lib/sprockets/rails/helper.rb:363:in `raise_unless_precompiled_asset'
```

all.js is not used in production mode, it's there as a convenience to help the
test runner.

alphagov/frontend,alphagov/frontend,alphagov/frontend,alphagov/frontend