Updated Login feature specifications

Login.feature

Feature: User login

Scenario: Entering credentials and clicking the login button
  Given an instance of our Login component
  And   a mocked implementation of the login method
  When  I enter a username
  And   I enter a password
  And   I click the login button
  Then  I expect the login handler method to be executed

Scenario: Logging in calls REST API client
  Given a mock instance of the API client
  And   a mock instance of the Vue router
  And   an instance of the LogIn component
  When  I enter a valid username
  And   I enter a valid password
  And   I click the login button
  Then  I expect that the username property is set correctly
  And   I expect that the password property is set correctly
  And   I expect that the userAuth method on the API client is called
  And   I expect that the Vue router has been called to navigate away from the Login