Fix Import Order

[skeet70]

If done following the docs, the client only works with the test sandbox credentials. The Processor and PaymentMethods explicitly have to be imported after the config/creds are set in a view. Should be laid out more plainly in the docs that this is required, or should be fixed so that import order doesn't matter.

ex:

import samurai.config as config
config.merchant_key = 'merchant_key'
config.merchant_password = 'mechant_password'
config.processor_token = 'processor_token'
from samurai.payment_method import PaymentMethod
from samurai.processor import Processor

^ Works.

from samurai.payment_method import PaymentMethod
from samurai.processor import Processor
import samurai.config as config
config.merchant_key = 'merchant_key'
config.merchant_password = 'mechant_password'
config.processor_token = 'processor_token'

^ Doesn't