Fix a minor typo in specs

There is nothing much to this one, it's in the test description so it shouldn't impact a thing and will make this line more greppable.

test/integration/authenticatable_test.rb

@@ -245,7 +245,7 @@ class AuthenticationRoutesRestrictions < Devise::IntegrationTest
     end
   end
 
-  test 'not signed in users should see unautheticated page (unauthenticated accepted)' do
+  test 'not signed in users should see unauthenticated page (unauthenticated accepted)' do
     get join_path
 
     assert_response :success