rake: add extract_fixtures task
schema: add level to bay elements
test_helper: add to_params,to_nested_params,etc
bays: add level to elements, test passed

fixed create/update nest'd bugs: :id param
fixtures: test passed
brands: test passed
categories: test passed
import_sheets: test passed
manufacturers: test passed
regions: test passed
stores: test passed
suppliers: test passed
merchandises: test passed
remove unused controller tests
Merge branch 'feature/add-tests' into develop