wip: added products to big commerce. hideously slow due to separate requests per image. code to interpolate is also too dense but will be splitting it into parallel soon:
Parallel BigCommerce Products using Typhoeus
Use credentials from faraday connection object.
Using Threads instead of Typhoeus Hydra
Remove Typhoeus
Threaded retrieval of big_commerce products

Also updated VCR, and fixtures
addes a spec for mapping multiple sources to the same model