Scope method should return cached relation value (sync)
hasMany through - sync scope getter
hasOne - test sync scope getter
polymorphic hasMany - test sync scope getter
hasAndBelongsToMany - test sync scope getter
embedsMany - implement sync scope getter
Test .value() method - as used by scope getter
Merge pull request #288 from fabien/fix/relation-tests

Test sync (cached) relation getters