v3.0.0

This major release changes the general philosophy of the project to rely on batching rather than includes.
Almost all use cases will experience great performance improvements.
There is a minor performance degradation in cases where the query is only one level deep with a single belongsTo relation.

• Removed prefetching/includes in favor of https://github.com/mickhansen/dataloader-sequelize
• Removed filterAttributes (use filter in before)
• Removed defaultAttributes
• Removed simpleAST from resolver info (use simpleAST user-side now)