pool.end() resolves before the last pool.query()

[ghost]

The pool.end callback/promise should resolve after the last pool.query resolves but instead it always resolves just before the last query:

pool.query(query).then(() => console.log('done'))
pool.query(query).then(() => console.log('done'))
pool.query(query).then(() => console.log('done'))
pool.end().then(() => console.log('end'))

result:

done
done
end
done

it needs to resolve after to signal that all query callbacks have run

another example of this occurring is in PR #2149 (comment)

I have not looked at solution again yet but maybe can sometime coming up, or anyone else feel free to fix