* added findAndReplaceInModels api call
* added documentation for findAndReplaceInModels
* added findAndReplaceInModels api call
* updatd findAndReplaceInModels function
* added unit test for findAndReplaceInModels in models
* updated findAndReplaceInModels
* added unit test for findAndReplaceInModels
* removed 'all_models' in findAndReplaceInModels