Improve 'update_all' 'delete_all' error message
Test transaction API should have optional opts
Don't send preload query for empty associations
Only type annotate empty SQL arrays
Enum.count on has_many associations shouldn't break
Merge pull request #192 from BjRo/fix_enumerable_count

Enum.count on has_many associations shouldn't break
created mysql files, highlighted places to replace driver with mysql driver