Makes validator on Spree::Product#permalink tenant aware
Upgrades spree 1.3.0 => 1.3.1

Also reorders dependencies in the Gemfile that used by the spec/dummy
test app.
Enures that model columns update before running db:seed
Deletes product data before running empty store examples
Adds spree_auth_devise for tenant user support

* Makes validator on Spree::User#email tenant aware
* Removes uniqueness database constraint on Spree::User#email
* Updates specs that need to access admin interface
* Ensures that app generated by test_app uses Spree::User

Note :This couples spree_landlord with spree_auth_devise and thus
devise. This support can be moved into it's own gem later, if needed,
but we're keeping it in here for now.
Adds support for tenanted user accounts