[MODEL] Added, that `each_with_hit` and `map_with_hit` in `Elasticsearch::Model::Response::Records` call `to_a`

The `zip` method in `records.rb` didn't call `to_a` on the collection,
thus the records were not returned in the same order as Elasticsearch's results.

Related #99
Related #102
[MODEL] Added tests for `each_with_hit` and `map_with_hit`

These are tests for commit 83831b3.

Closes #99
Closes #102