Default Braintree configuration on store creation overwrites custom configuration

[mdesantis]

Building the default Braintree configuration record on store creation doesn't check whether a braintree configuration already exists:

solidus_paypal_braintree/app/models/spree/store_decorator.rb

Lines 4 to 10 in 73e9a69

	before_create :build_default_configuration
	private
	def build_default_configuration
	build_braintree_configuration
	end

overwriting a custom configuration on store creation:

store = Spree::Store.new(
  code: 'some unique store code',
  name: 'name',
  url: 'example.com',
  mail_from_address: 'store@example.com'
)
store.build_braintree_configuration(
  credit_card: true,
  paypal: true,
  apple_pay: true
)
store.save!
store.braintree_configuration #=> ... paypal: false, apple_pay: false, credit_card: false>