Create literal-in-included-model-attributes.js

This is failing test for using `Sequelize.literal(...)` as one of attributes in model that is included in another model (via `include`). It seems that sequelize does not checks if any attribute of included model is instance of `Sequelize.literal()`.

There are actually 2 test in this file:
1. First one passes because `Sequelize.literal` is in root query model attributes
2. Second one fails because `Sequelize.literal` is in query included model attributes
remove `.only`