* allow services to export >1 classes
This change to loadServiceClasses() allows us to define
services which either export a single service class e.g:
module.exports = class Cdnjs extends BaseService {
//...
}
or more than one. e.g:
module.exports = {
GemVersion,
GemDownloads,
GemOwner,
GemRank,
}
* refactor ruby gem badges
- move badge code to service classes
- throw exceptions for errors
- use let and const
- change tests to expect 'downloads' label for error badges
- general tidying
* fix typo in tests
* Don't always use class name in example label
This allows (for example) GemVersion and GemDownloads
both to use the example label 'Gem'
