message: repositioned role=menuitem to within OsfLinks for menu, added role for Sign up and Sign In buttons.
diff: {{@headline}}
  </ddm.item>
  {{/if}}
  - <ddm.item role='menuitem'>
  + <ddm.item>
  <OsfLink
  data-test-ad-my-profile
  data-analytics-name='MyProfile'
  @href={{this.profileURL}}
  + role='menuitem'
  >
  <FaIcon @icon='user' class='fa-lg p-r-xs' />
  {{t 'auth_dropdown.my_profile'}}
  </OsfLink>
  </ddm.item>
  - <ddm.item role='menuitem'>
  + <ddm.item>
  <OsfLink
  data-test-ad-support
  data-analytics-name='Support'
  @href={{this.supportURL}}
  + role='menuitem'
  >
  <FaIcon @icon='life-ring' class='fa-lg p-r-xs' />
  {{t 'auth_dropdown.osf_support'}}
  </OsfLink>
  </ddm.item>
  - <ddm.item role='menuitem'>
  + <ddm.item>
  <OsfLink
  data-test-ad-settings
  data-analytics-name='Settings'
  @href={{this.settingsURL}}
  + role='menuitem'
  >
  <FaIcon @icon='cog' class='fa-lg p-r-xs' />
  {{t 'general.settings'}}
  </OsfLink>
  </ddm.item>
  - <ddm.item role='menuitem'>
  + <ddm.item>
  <BsButton
  data-test-ad-logout
  data-analytics-name='Logout'
  class='logoutLink'
  @type='link'
  @onClick={{action this.currentUser.logout}}
  + role='menuitem'
  >
  <FaIcon @icon='sign-out-alt' class='fa-lg p-r-xs' />
  {{t 'auth_dropdown.log_out'}}
  class='btn btn-success btn-top-signup m-l-sm m-r-xs'
  @route='register'
  @queryParams={{this.signUpQueryParams}}
  + role='button'
  >
  {{t 'auth_dropdown.sign_up'}}
  </OsfLink>
  @onClick={{action this.login}}
  @size='xs'
  @type='info'
  + role='button'
  >
  {{t 'auth_dropdown.sign_in'}}
  </BsButton>
  