Use user.id as CustomerId because emails can go over the 50 char limit
Merge pull request #7 from CultConspiracy/user-id-as-customer-id

Use user.id as CustomerId because emails can go over the 50 char limit
Fixes issue ue with guest orders
Removes spork
Fixes failing spec
Adds Config.shipstation_number option
Updates readme with info about Config.shipstation_number setting
Adds shipping method name to custom fields
Updates how we send shipping method
Revert "Updates how we send shipping method"

This reverts commit 3c32034bb6910d6ab92f16f3f661091941e6cac1.
Revert "Adds shipping method name to custom fields"

This reverts commit 45363c55745884940e772a3be56eb909c4af628d.
Updates xml to allow empty shipping method
Updates Shipment.exportable scope to join orders table
Adds paging support for exporting
Allow all spree versions >= 1.3