QA: Fix missing "Given I am logged in as a new user"

Echo browser tests pass, but are skipping
  Scenario: New user gets a sign up notification
because a step definition is missing.

I simply adapted
  ^I am logged in as a new user with no notifications$
and the scenario passes in chrome.

Change-Id: I9f2bd10d05b689eaacbf2890913786eb157d6af9