Add test cases for Schematic and tweak Schematic class.
Add schematics to global test.
Add Product.find_or_create method.
Convert product seed functions to YAML.
Add load from yaml and save to yaml functions.
Change find_products_by* and find_product_by* methods to just find_by*.
Update test to use find_or_create and find_by* methods.
Update schematic test to use Product.find_or_create.