Each example should have its own endpoints.yaml file

[php-coder]

Pros:

1. endpoints.yaml for language without types won't contain additional information about fields types
2. allows us to add a new feature gradually (by updating relevant endpoints.yaml instead of a global one)
3. later it will help us to detect changes only for particular language and skip other tests
4. it became possible to use different SQL queries. Especially useful for SQLite (Support SQLite #53) that doesn't have NOW() function
   Cons:
5. duplication
6. the integration tests also should be split