Fix #1611 (Rephrase error message for people logging in with an existing user email)

update test to use new rspec syntax

config/locales/en.yml

@@ -60,6 +60,12 @@ en:
       spree/order:
         payment_state: Payment State
         shipment_state: Shipment State
+    errors:
+      models:
+        spree/user:
+          attributes:
+            email:
+              taken: "There's already an account for this email. Please login or reset your password."
   devise:
     failure:
       invalid: |

spec/features/consumer/authentication_spec.rb

@@ -60,6 +60,13 @@ feature "Authentication", js: true, retry: 3 do
             page.should have_content "too short"
           end
 
+          scenario "Failing to sign up because email is already registered" do
+            fill_in "Email", with: user.email
+            fill_in "Choose a password", with: "foobarino"
+            click_signup_button
+            expect(page).to have_content "There's already an account for this email."
+          end
+
           scenario "Signing up successfully" do
             fill_in "Email", with: "test@foo.com"
             fill_in "Choose a password", with: "test12345"