added GetCustomers endpoint to cart
started on CRUD functions for customers in the cart
Merge branch 'master' of https://github.com/curt-labs/GoAPI

* 'master' of https://github.com/curt-labs/GoAPI:
  begins customer_new/user controller tests
  adds brand model and tests for it
  adds custoemr_new/price controller test; changes price/sales to post request.
  finishes customer_new/location controller test