This moves a few helpers from `lib/` to `services/`:
build-status.js
build-status.spec.js
color-formatters.js
color-formatters.spec.js
contributor-count.js
licenses.js
licenses.spec.js
php-version.js
php-version.spec.js
text-formatters.js
text-formatters.spec.js
version.js
version.spec.js
And one from `lib/` to `core/`:
unhandled-rejection.spec.js
The diff is long, but the changes are straightforward.
Ref #2832
1. Add validation to BaseSvgScrapingService and update readthedocs accordingly.
2. Rewrite vso and add more tests. Rename it internally to azure-devops. URLs are still `/vso` for now. Should we make a way to let a service register multiple URL patterns?
3. Handle shared code using a functional pattern instead of inheritance. This comes from a discussion https://github.com/badges/shields/pull/2031#issuecomment-417893819. I like the functional approach because it's more direct, nimble, and easy to reason about; plus it allows services to grow from a family of one to two more easily.